I started playing about two years ago. I usually play support, because it is the role I find most interesting (being all about others and such) and because it is what most pub games lack - usually people don't pick supports at all or they don't do it properly, and there's few things so irritating as the lack of wards :)
My favourite hero, and the one with which I am more succeful, is Crystal Maiden - so I wrote this guide to help those who want to start playing with her, or to give new perspectives to those who already play her. Since I wrote its first draft, I've been learning a lot, with the comments people generously gave me, and having to explain my gut thoughts on Crystal made me look at her ever so more carefully.
Here is my Dotabuff profile, if you're interested in checking out my games with Crystal.
English is not my native language, so excuse me for any mistakes. Naturally I would very much appreciate comments on how you would do things differently (and if you want to correct any gramatical error too please be my guest!)
CM's importance is evident: she is one of the heroes most frequently played in Championship games, because she is flexible enough to go well in most teams, and can be everything you need in a support.
This guide is intended for both the new-to-Dota2 players and for the already experienced ones. Crystal Maiden is a relatively easy hero to play if you're new to the game, but to really get the hang of her and learn not to die so often and still make a diference it takes some time. If you're new to Dota, I suggest you read the famous Welcome to Dota, you suck guide by Purge, that you can find here.
Also, the style I'm more inclined to is the typical baby-sitter in lane for your carry, as you will notice throughout my explanations on items and the skill build. However, you can also adapt my choices for a roaming/jungle style, and I talk about these in this guide too.
Some people told me this guide is too long for a full reading, but I just hope that if you're in for a quick info on something you will be able to find its place easy and quickly enough.
Crystal Maiden is what is usually called a hard support (or a 5 in the farming priority system). That means that, no matter what your preferable style with her is, she will always be more efficient if you play her as the humble support, fully devoted to your team. It can happen that a 5 hero doesn't get to purchase nothing more than a Boots of Speed and a Magic Wand for themselves for a bit part of the game, if it is a demanding one. As Rylon Crestfall said, she's a "easy to understand, hard to master" kind of hero.
Even though every hero benefits from farm and kills, at the end a six slotted CM will not win the game for you, and you can even lose the game for your team, if you're the one that is getting all the kills. A good teamfight will be the one were you're the only one dead on your team, having been able to use all of your abilities before you die. A good game will be the one were you always know your opponents movement because you've warded the map accordingly, that slippery invisible foe is always revealed by your dust and your teammates are - surprise! - being cured by you all the time (because of the Urn of Shadows I like to think a core item for her).
If you're learning how to play this hero beware of her main problem, survivibility, and try not to feed, even at the cost of your utility; once you've learned to survive, you can begin to gradually play more aggresively. Unlike what most people think, the support role is not necessarily easier than the other roles, because you will have to learn to rely on your skills with next to no items, while learning technicalities such as how to properly ward, deward and pull/stack. Also, to use Crystal to her full potential you will have to learn one of the most difficult things in Dota: positioning. If you have trouble with this, or if you don't even know what I mean by it, consult guides such as this.
Crystal Maiden's role is to make the others shine (by so doing, being able to shine too at times). I think she is underrated because many people get frustrated with her fragilty and the fact that she rarely gets to be the star of the game, but that is exactly one of the things I like the most about her - she represents what a pub game usually needs the most, the unselfish support. She is a very succeful hero (around 56% win rate according to Dota Buff) and one of the most picked both in pub and competitive games.
Since some patches ago Crystal Maiden has been buffed non stop - the last buff was with Patch 6.87 that reduced the cooldown from Crystal Nova even more, and augmented the regeneration of the Arcane Aura. These buffs were not exactly needed, since the hero was already at a good spot, but it helps her to face the challenge of keeping up with other support heroes, such as Vengeful Spirit and Lion, who have sweeped the meta in their favour, because of their versatility and what they have to offer late game even if completely farmed starved (CM can also offer a lot of utility, but she somehow falls off in the really long games if she has nothing to help her survive).
For a time, for me Frostbite was the bread and butter of CM. Inspite the fact that it is not a real stun, it basically works as one: it has a mini-stun when casted, followed by an inhibition for the target to move or attack (altough it can cast abilities). Since it has the mini stun, it interrupts channeling; what's more, it reveals invisible enemies for the duration. Even if your target blinks, he will be left some meters away from you, still encased in the ice - happens frequently with Slark and his Pounce (note that some blink abilities are disabled anyway, such as Queen of Pain and Anti-Mage's blink and the blink from Blink Dagger). Frostbite also deals 50 damage every half-second, which is negligible when considering heroes in the late game (it only lasts 3 seconds on them, that is, 300 damage), but is essential for your very-quick-no-one-is-looking-nor-needs-this-neutral-creep-iei-more-wards-money farm (it lasts 10 seconds on all creeps).
I take the first point in it because when the game begins, your main role is to help the teammate you're babysitting, either by harrasing enemies (helping him to farm more efficiently), by securing kills or by making sure he doesn't die. Frostbite is all that: if your pair is feeling confident to go on someone, it works like a stun; if you are afraid something bad may happen, you can keep it for an emergency run. Just be sure to not waste it on those first minutes of the game just for the harrasing, since you will not be able to spam it just yet (you have just one Frostbite until some time is passed or gain enough XP for level 2). However, if you go for that first Bounty Rune, it will help you gain it, deny it or just live to fight another day.
As the game progresses, you will know better if you need to maxed it out first(if you feel you can profit from the extra duration because you can either get a kill with it or need it against blinkers) or if you can just max it out last. In my current core build I max it out last, because with the changes of the new patch 6.84 her Crystal Novaand Freezing Fieldare worth maxing first (you want a slow of 50% plus nuke as soon as you can get it, and the ultimate's mana cost can now be solved with Enchanted Mangos).
However, against blinkers such as Anti-Mage, Faceless Void and Queen of Pain, or if you're up against an offlane without an escape mechanism which you think you can kill (for instance an Axe), you should max out Frostbitefirst, for the extra duration, extra damage and lesser cooldown.
Arcane Auramaxed will make everyone love you, for obvious reasons. I prefer to take it at level 2 and 4 not only because of the advantage it gives to your allies (most heroes will have infinite mana with only this ability and just a Ring of Basilius in their inventory - try Bristleback and Weaver, for instance) but also because it allows you to spam your abilities on every cooldown, and still have enough mana for Freezing Field, if needed. Although you can of course alter the skill build depending on your preferences or what the game is demanding, I've found that taking the aura at level 2 is preferable to almost everything else: if you take it at level 1, even if it doesn't change must, you will be left with no spell at all for that first clash at the runes; if you take it at level 3 or later you will have no mana to use your skills as often as you could. With this skill build I have never needed to buy Clarity for me or my teammates the whole game, which I think is a natural and desirable result considering we are talking about a hero with a passive skill just to boost her mana regen (and also Claritys can easily be interrupted while you're doing your stuff like harassing in lane or simply pulling).
With this build, at level 6 you can do your whole combo in sequence and still gain rapidly sufficient mana to start again, if you carry an Enchanted Mango.
Crystal Nova was the skill I was less passionate about CM, until they buffed it. A lot. Now it is a nuke that slows enemy movement and attack speed by a freaking 50% in a targeted big-circle area. The problem with it is that, if you max this one out early, you're going to be inclined to use it for farming the lanes (it's very good for last hitting), and that is perfectly normal, except you will be doing what everyone dreads the most about supports: unnecessarily taking the farm that otherwise belongs to your carry teammates. Also, it is a skill that costs a lot of mana when combined with Frostbite. Hence my current core build: max it out asap, with only one point in Frostbite until later for its utility and some points in the Arcane Aura so you're able to sustain your mana needs.
Thus, level 4 is the level I consider CM to be at her finest in the early hour: with one level on Frostbite and Crystal Nova and two levels on the Arcane Aura, you can harass your enemies at will, not bothering with mana regen items whatsoever, restrained only by the cooldown of the abilities, and more easily secure a kill (which should precisely be happening by this time, since your mid teammate will have reached level 6 and will be ready for ganking, if everything went allright).
To sum up, max it out first, unless there is some reason to alter this (like blinkers). Maxing it out early will give you enormous utility in teamfights, since you will be nuking and slowing for 50% (also nukes, per definition, are better in the early game, since later everyone's HP points will be increased to the point where you only do scratch damage with this).
Speaking of which, fun story plus tip:
Tip on Crystal Nova
One of these days, playing against a Lifestealer with low HP running away from me after a teamfight, I was able to kill him because, out of a lucky on-the-spot reasoning, I leveled up Crystal Nova instead of the usual other skill on level 7 while chasing him, having realized I was not going to be able to get him in Frostbite's range. So I profited from the longer round range and nuke damage of level 2 Crystal Nova. Thus, my tip here is don't forget Crystal Nova's range is superior to Frostbite's.
A large area around Crystal is afected by explosions that slow the enemy's both movement and attack speed, and that deal lots of damage.
Her ultimate turns CM into a dangerous opponent in teamfights: altough she is extremely fragile, she can also deliver a surprisingly huge amount of damage - if she can channel her ultimate properly. Hence the problem: how to manage not being interrupted by all the disablers you surely will be facing. There is no easy way to answer this, but here are some obvious tips that may be useful.
Tips on safelly channeling Crystal Maiden's ultimate
Stay at the back of the fight and let the disablers use their spells before coming in with your ulti (either on the edge of the fight or jumping in with a Force Staff or Blink Dagger);
Try to use the terrain you're fighting in to your advantage: stay high ground or beyond trees if possible, as long as you still can reach the enemies ( Freezing Field has a Radius that, as CM herself, is often underrated);
Buy a Glimmer Cape and activate it before or after casting your ultimate, since it does not interrupt it.
Before I would only take this skill at around level 7 or 8 instead of at the possible level 6, because of mana issues, but right now you can simply carry an Enchanted Mango with your and this problem is solved, since you will almost never start the fight straight with your ulti, but it doesn't matter if you're in the middle of it taking damage, Enchanted Mango is instantaneous and doesn't get interrupted.
This being said, consider some possible scenarios where you can take your ultimate later, or how you should proceed about it:
Scenario no. 2: Unexpectedly, you're facing enemies with no power or apparently no skill to interrupt your channeling - a team composed of, let's say, a Shadow Fiend, a Weaver, a Bristleback, a Dazzle and a Viper (also having no blink, probably Weaver is the only one who would be able to escape alive from your ulti). The game is going in your favour and some team battles have already taken place. Taking that ultimate at level 6 in this case may just be the thing you need to deepen the gap between your team and theirs - few people expect a CM's ulti this early, and hardly will already have the power to kill you quick enough to avoid the full damage.
Scenario no. 3: This time you're up against heroes that do have disables but tend not to save them in teamfights, since they heavily rely on them to initiate, like Rubick, Axe, Centaur Warrunner and Chaos Knight. You probably can risk leveling up your ultimate asap and save it for after they've used their disables.
Scenario no. 5: Even if you have already taken Freezing Field at level 6, you simply cannot ulti anymore because your disabler enemies are all over you and always save some sort of disable (be it a stun, hex, silence or similar) to trash it. Since there are so many kinds of disablers possible, I will just name some heroes specially annoying in this regard because they have more than one way of stopping you with their spells ( Earthshaker, Vengeful Spirit, Enigma, Lion, Shadow Shaman, Batrider, Earth Spirit, Disruptor, Kunkka) or stun you with normal right-click attacks ( Sniper, Faceless Void, Spirit Breaker, anyone with a Skull Basher). Don't get desperate. Save your ulti, consider passing it when leveling up on level 11, and get its second level as soon as you can have a Black King Baror a Glimmer Capeset to go. If the game does not permit you to purchase this, either because you're dying a lot or because you need the money for the support role (it is a ward-demanding game), or even if your BKB is just useless (that Doom BKB-passing ultimate is always specially saved just for you): just relax. Focus on staying alive a bit more, thus possibly gaining the chance for a well-placed ulti after the initial clash, when all the disables have already been used. Your ultimate is awesome, but you are still very useful to your team without it (I have seen some Championship games where CM simply cannot use it more than 1 or 2 times without being instantly interrupted).
Altough it may not seem so, it is a flexibly ultimate: you can use it to contribute with damage or slow to a teamfight, to create some safe space for your teammates to fall back from a hairy situation, to trade your life against someone as fragile as you when you know you won't be able to escape or even, in rare situations, offensively, to destroy someone when you see the opportunity - when you're facing someone with no chance of escaping by spells and it is not probable he can kill your first. An example of this would be (rejoyce, oh supports!) when you encounter a fragile alone carry with low health and no way of interrupting you ( Phantom Assassin, Clinkz, Enchantress), or a mage that equally has recently used all his spells (a Zeus or a Leshrac, for instance). However, note that this situation will most likely be very rare, and if you're new to the hero don't risk it, since it is a high risk-high reward move; your teammates will be buggin' you if you end up dead first or can't secure the kill and are left with no ultimate to use on the next teamfight. Try not to use it out of panic when you're dying - if you're dead anyway too rapidly to take someone down with you, no point in wasting the rather long cooldown.
The more agressive style
I have prepared an alternative skill build, along with some items indications, to take into consideration some builds I've seen working on pubs and on the competitive scene. I've called this the "If u have help supporting and like to be more agressive" build, because I think it does not use CM potential to her fullest, trying instead to buff her in the aspect she lacks - it ignores until later one of her biggest contributions to the team, the aura mana regen, and boosts her damage and/or stats, which is not exactly the reason why you would pick CM.
Altough I don't like it as much as my preferred build, it can shift CM from a support that is more passive alone and dependent of the team to someone who roams and ganks independently with more ease. Essentialy, in this build you will want to maximize Crystal Nova first, as the main source of CM's damage, followed by Frostbite (don't forget it as a jungling farming tool), generelly leaving only one point in Arcane Aura until later just to be able to use the ulti latter on with nothing more than some better stats and a Magic Wand for regen.
The chosen items go hand-in-hand with this approach: Power Treads or Phase Boots for better stats, attack speed or mobility, and items that grant stats and a more offensive way of playing (like the Shadow Blade - or even a Veil of Discord can be a good idea, when you're able to use your ulti properly).
As a support, you will be expected to start the game with the usual support stuff. I always purchase first the Observer Ward in order to control them: I either distribute them to teammates who will put them on each side of the map, or by keeping one to myself and giving the other to the midlaner, the other support or whoever asks for it. You can share them all at a time (by dropping them on the ground) or one by one (by Alt-Clicking on them and then on the person you want to give them to). If you don't buy them first someone else can do it, and there is a risk he will not share one with you (pub games, you know how it is...)
Next you're going to buy your regen of choice. I prefer a simple set of Tango because they last longer in lane, are not interrumpted in case I'm attacked while chewing on one, and because like this I end up with enough money for the Ring of Protection. If you are not confortable with only this regen, don't forget you can always buy more a bit latter (the clock ticking means money, even if you don't last hit one single time).
After the Tangos, you will generally buy the Animal Courier, unless another support offers to do so - be sure to always ask about this before buying it so your team will not end up with a second unnecessary courier. I like to try and favor a good vibe for the team since the beggining, so If I ask someone to buy the courier as CM I also thank them and promise to be the one transforming him into Flying Courier. In that case, either buy an Enchanted Mango for that early HP regen and emergency mana, or go ahead and buy a Gauntlets of Strength (since CM never complains about some extra HP and you can turn them later into an Urn of Shadows).
Until here there is nothing really new, as most CMs will buy those. But now my favourite personal choice: for that extra armor CM lacks so much, a Ring of Protection. Presently, I almost always start with these items: I try to play it safe enough to be able to stay in lane sparing as much as possible the Tangos, and if some more HP regen reveals its urgency before I am able to finish my Tranquil Boots, I can always buy some more Tangos or a Healing Salve by then. The Ring of Protection, on the other hand, really helps CM staying alive and suffering less from creep attacks when she harasses the enemy, since it transforms her 1 starting armor into a 4 armor, helping you to harass your lane enemies, exchanging hits with the ranged ones. It is a good purchase also because it is a piece of your next big item, your Tranquil Boots.
Now is the time to again remember you of the (numerous exceptions) to the purchase order and items contained on what I consider the core build for Crystal Maiden, plus of this important fact: not only your role is to support but you're considered the paragon of the hard support. That means you will have to, more than helping with the ocasional ward, buy it EVERYTIME it may be necessary (eventually, everytime it is on cooldown). You may be disappointed when you realize the Witch Doctor or Pugna on your team is not helping you with the support, but nevermind them and their I-can-carry-too mentality, you're the one everyone's gonna complain about at the end and if no-one else is gonna do it for you, you just got to step forward, and put your team needs before your personal item needs.
Now that the disclaimer is out, some possible scenarios to consider when thinking about your item purchase order:
Scenario no. 1: The game is going fine, you have one or no Tangos left and have just enough money to complete your Tranquil Boots: go ahead (not before you up the courier though, unless you really need to prioritizy them cause you've run out of HP regen). They are your main and possibly only indispensable item. Since you are slow as a snail, you cannot pass out on Boots of Speed, if you want to ever have a chance on accomplishing something (may it be to run away from the predicted gank, or simply walk to another lane in less than 5 minutes). Also, these are the cheapest boots (once again, you're the support, money is an issue) and you will be using them throughout the game to regenerate your life in between fights by not auto-attacking for a while (your auto-attack is so insignificant you won't miss it and can continue to farm on the lane with your spells).
Scenario no. 2: You're laning against a Riki, Broodmother, Bounty Hunter, Weaver, Nyx Assassin, Clinkz, Templar Assassin or Sand King. Not only they are invisible, they get extremely offensive while at it (as opposed to, for instance, Treant Protector, who will not be expected to be using his invisibility offensively just yet, or Invoker, who uses his invi ability mainly to gank and escape). This also means Mirana in the other team, because you may be facing a gank as soon as she hits level 6. You're advised to buy Sentry Wardas soon as you have the 200 gold needed, and hold on to them for the time being or place them immediatly as you deem best in your lane, to protect you and your teammate of a not welcome initiation.
Concerning invis, see the tips I've prepared to counter invisible heroes in the Foes section.
Scenario no. 3: Techies. THAT BASTARD. He deserves a special mention since you're going to be needing a LOT of Sentry Ward to be able to just walk the map, and Observer Ward to spot him before he places those dreaful mines, and these take precedent over your other items.
See the tips I've prepared to counter him on the Foes section.
Scenario no. 4: You are facing some probable near future ganks, as the other team has a mid Pudge, Invoker, Puck, Slark, Queen of Pain, Storm Spirit or someone of that kind - mobile, damaging and ganky. If the ward you placed to secure your lane has already expired or is near its expiration hour, consider again putting off your Tranquil Bootsjust a bit longer for that refreshed Observer Wardwho may just save your lives.
Scenario no. 5: Here comes Bristleback, Weaver, Silencer, Zeus, Disruptor, Batrider, or any other Intelligence hero who spams his spells a lot, facing you in your lane. They will want to use their abilities as often as possible because they rely on them to either farm/harass/secure the lane, and that means charges for a Magic Stick and after a Magic Wand. Altough my core build does not include it, because I generally prefer other items over it, I always buy it in this case because it will be very useful, as you will gain a free way to regen HP and mana throughout the laning phase, at the same time countering, in a way, these difficult opponents.
Now it is time for you to sit back and relax: if you're skilled, anything that comes after this will only help you do with more elegance what you should be doing anyway. And that's one of the magics to the support role: no need to really stress over farming that big next item that will get you the game.
I like this item a lot because everything it has is usefull to CM, at a cheap price:
It gives 6 strenght, which means 114 health and 0.18 health regeneration (not bad for this squishy lady);
It gives 50% Mana regeneration (usefull if you have mana burners on the opposite team or just like to spam a lot all the time like I do - you won't be needing any other mana regen item, if you know how to manage your mana pool);
It has the active ability of gaining 1 charge every time an enemy hero dies within a 1400 radius, and that charge can be used either to heal a teammate (400HP) or damage an enemy (for 150 pure damage).
The fact that it can be used to cure allies makes CM a complete support (having stun, aura, slow and healing). I buy it almost every game, with the exception of those games where there are other powerfull healing spells (such as Witch Doctor's, Huskar's or Juggernaut's) or a teammate is purchasing it too (only the closest Urn will gain the charge), which happens a lot when there is a Pudge, a Spirit Breaker or an Enchantress. In the late game you can sell it to trade for something more interesting, as its healing loses much of its initial value because everyone's HP and HP regen is boosted (also don't buy it past the mid game for the same reason).
Don't forget to use it when you're running away in a tight situation just after a teamfight or even in the middle of it, because your Tranquil Boots will be in cooldown and that extra HP points may save your life (for example, you can prevent an unexpected death from a Sun Strike or a Thundergod's Wrath).
Tip when buying an Urn of Shadows
Since it is composed of a Sage's Mask, a shareable item available in the Side Shop, consider buying this as the first piece and share it with your lane partner when he needs some mana regen(simply by Click Draggin it to your partner's hero). He will benefit from the regen effect as you would, but not be able to complete any item with it. No problem: when his mana is back up just ask him to give it back to you.
We already explained Crystal Maiden is one of the slowest heroes, and that is is unfortunate for anyone: in Dota, positioning is key to success. You will need to be behind every line of fight just enough not to be picked by the enemy carry first, but close enough to land a spell and not be surprised by that same enemy too far behind your team. Particularly, your ultimate, to be effective, must reach the hightest number of enemies possible, and that means being in the center of the fight. Any positioning item will, therefore, help Crystal so much that I consider it your second core item.
Some people prefer to buy a Blink Dagger, since it allows for a more precise displacement (that is why is often seen in the competitive scene). Others buy a Shadow Blade, that can be used either to enter the fight or to use after beggining to ulti (it will not interrupt your channeling). Now you even have an alternative to this, the Glimmer Cape (helping you channel without having to buy a BKB).
Summing it up real quick, I would tell you to:
Go Force Staff if you're in a pub game, because its pieces are cheaper and life-savior, or if you're in a game where most people have Damage over time (DoT) that can hurt your possibility of getting away with a Blink;
Go Blink Dagger if you're in a party or if you're ahead in the game and want that extra precision to gank and play more aggresively.
With this explanation I tried to really break it out in simple terms, since I go for either item in games based on this reasoning, and also this is why Force Staff is a safer option in most games and therefore core, whereas Blink Dagger appears on the "perfect ending game" build. I will try to explain it better in the section on positioning below.
As for the order you will purchase the Force Staff, you will generally want to acquire first the Staff of Wizardry, because it is the most expensive and more useful of Force Staff's pieces. Anyhow, if you end up buying the Ring of Regen or Recipe first, just leave them on your stash on the fountain, if you're having trouble managing your slots (happens more frequently than you would expect even for a Crystal Maiden).
If mobility is your thing, go for both Force Staff and Blink Dagger; there are various CM played by competitive players that do it, and this way you can blink in and force staff out, in case of need.
Tip on the use of Force Staff
Don't forget to use your Force Staff, when everything is calm, just to move around the map more quickly. Also, don't forget you can use it on allies (to help them catch that running enemy or flee) or on enemies (to start a fight "fishing" out someone or to take them out of the fight, disturbing its play).
Besides these, you must always carry the Observer Wards we've talked about so much (including Sentry Wardfor counterwarding, which we will talk about in theGameplay Section), and don't forget Smoke of Deceitnow and then, to gank that enemy farmers you know are in their jungle farming safely or to secretly do a safer Roshan. You will easily have the amounts necessary for these type of consumables just by waiting on the time-passing gold or farming a camp of neutrals if needed, and the beauty of it is that you can perform an excellent game with nothing else.
The perfect game
The perfect game is not easy to come by. I have had some pretty good games with CM, and still only reached this 6 slot a few times. Generally, even if you do a 8-2-20 game, you will end up with only one of these, because you: i) always prioritized the farm of your teammates; ii) spent gold with support consumables the entire game. Anyway, I think it is important, for any hero, to look up to something like the "perfect build", in order to have some insight in what you should be looking up to.
Although the first item in line, it will usually be the last to be bought. If you have everything else and still money to spare, consider carefully between saving for a buyback (yes, even if you are Crystal Maiden you can take this into consideration, like the pros) or getting this item to more quickly join your teammates in fights. The same can be said of Upgraded Boots of Travel- their cost is so high you will probably never buy it just to be able to teleport to friendly heroes, but if your team strategy benefits from them, don't hesitate.
Next to the Force Staff, this is the item I have bought more frequently on Crystal Maiden. As you know well enough by now, one of CM's biggest problems is the fact that her ultimate requires channeling. With a BKB, few abilities will be able to interrupt you. The Mithril Hammer can be hard to squeeze into your game (1600 gold for a piece that only grants damage) but the 10 Strenght points the Ogre Club gives will be much welcome at this stage of the game, where your fragilty makes you even more vulnearable to those damage dealers.
Beware of those abilities that can interrupt your channeling and that will still pass through BKB:
If you're suffering from one of these frequently, or if you're dying to a specially damaging ulti that deals physical damage or that isn't blocked by the BKB (such as Omnislash, Exorcism, or Death Ward), there is no point in wasting money on it.
As a rule, I would say only buy it when you're having no troubles channeling your entire ultimate;, either because you're lucky, very skilled or because you already have the BKB. This means it is an item that I pick rarely, but still would appear on the perfect game, as it gives you very nice stats that will help you survive more often the big clashes (10 all Atributes, plus 200 HP and 150 Mana), and its pieces are not that difficult to buy (three times 1000 gold plus the 1200 gold Point Booster).
The first piece I generally buy is the Point Booster, because at this time I already have my Inteligence boosted by the Force Staff and I like the extra HP and mana points. However, if you're afraid you will die with the money at any moment, or you're just not sure if you're doing an Aghs after all, go for the Ogre Club first, because if you decide not to buy an Agh's after all you can just hang on to that shanky piece of raw strenght. If you do not have any Inteligence item, go for the Staff of Wizardry instead.
I have compleated this item very few times too, usually ending up with only the Platemail. That happens not because it isn't a very good item on CM - it is, more Intelligence and Armor is perfect on the late game - but because one of its pieces, the Mystic Staff, is so expensive (2700 gold). It can thus be considered a Luxury item, one that you will try to achieve starting with that armor piece that you can keep until the end if you never get the money to buy the rest (of course it also synergizes very well with your ultimate, since it does not interupt the owner's channeling spells upon cast - imagine your enemies slowed to death!).
Notice that even in this build I filled a slot with Observer Ward: you should aim to always have an empty spot, for the consumable your team needs the most (be it normal vision or invis detection) or for a Town Portal Scroll. I haven't really talked about this because it is not something particular to Crystal Maiden and you should have assumed it by now: in Dota, as much as positioning is key, carrying a TP can also be the diferenec between victory and defeat.
Tips on acquiring post-core items
If you have all you consider core and some extra money but are unsure on what to purchase next, try an Ogre Club: not only you always welcome the extra HP points, but also this item can transform into one of two items CM adores: the Black King Bar and Aghanim's Scepter. You can thus keep the Ogre Club and gain some time to decide between one or the other, respectively if you're having troubles channeling your ultimate or not.
Another item you can always make use of is a Platemail: as a mage, CM will have next to no armor until the end of the game and this 10 armor, coupled with some extra Strenght, will greatly increase CM's survivibility.
Ask your teammates what they think. Don't be afraid of coming out as a noob, nor consider their opinions orders; their insights may be of very good value and tell you what is missing for the team rather than what is missing for you.
The most frequent anti-right clickers item. By entering ghost form, you cannot be attacked for 4 seconds (although you can still be attacked by spells, and even take extra magic damage). This allows you to enter the teamfight, cast your spells and try to run out of there alive, or even better: be courageous, jump into the fight, active your Ghost Scepter and do your ultimate. Your enemy will either try to run or to hit you, and if he can't hit you by those initial seconds he will take a lot of damage and probably be confused and try to run (what will be even worst for him). Very important: do not activate your Ghost Scepter after you ulti, because it interrupts channeling. It is an item relatively easy to buy (1600 gold at once) that grants you 7 points to each attribute (that is, 133 health, 0.21 health regeneration, 0.98 armor, 7 attack speed, 91 mana, 0.28 mana regeneration and 7 attack damage). The down side of this item is the extra magic damage taken: don't use it if you're being focused by high magical damage dealers, such as Skywrath Mage and Outworld Devourer.
Ok, first time you use it, it will probably not help you staying alive - but you will take someone down with you. No one will expect a CM carrying a Blade Mail, and don't underestimate its power: most damage dealers are quite fragile themselves, and after they understand you have a Blade Mail they will avoid hitting you first if they know you can activate it. If you're thinking "what a stupid idea, buying a Blademail on a support!" - my friend, I have been there too, but fortunetely enough bothered to try it just for fun, and BAM, I watched Phantom Assassin shrink of terror before me and run, and a Lina turned to ashes with her own ulti, while I stood there with 10 HP laughing.
After careful thinking and more experiences, I understood why it can be so good in some cases:
It deals the exact same amount of damage you take back to your foe, be it magical, physical or pure - and most damage dealers don't want to see that same damage returned;
It gives you more Inteligence and Armor, both things you really want in a CM, plus damage (consider it just a surplus);
Its pieces are rather unexpensive (the Broadsword is the most expensive one, but even so it costs only 1200, so it is not an impossible item to complete).
Of course that, as it happens with all other item choices, you must think carefully before buying it, since building a Blade Mail against someone whose HP is always going to be high (like an Axe) can be useless (also I advise against buying it in the late game, since).
Pretty common item on CM, on pubs and on championships. It gives her a disable that can also save her life against the damage of lethal right clickers, coupled with Inteligence stats and more movement speed. The reason why I usually avoid buying it with Crystal as a core is the fact that I think the 150% mana regen is a waste on her, since she is already the hero with more mana regen on the game naturally. I also prefer Force Staff on the subject of movement and Inteligence. Even so, it is a wonderfull item when you want to escape an attacker long enough for your team to arrive, or to dodge specific area located spells (such as Invoker's Chaos Meteor, Kunkka's Ghost Ship or Skywrath Mage's Mystic Flare).
Armor is always very good on CM, who at level 25 has only 9 natural armor. Of course, it is specially important if you're facing physical damage dealers. Platemail is the item that grants more armor at less cost (1400), which is affordable even for a support, and can be later turned into that Shiva's Guard we've examined earlier.
Although I personally prefer the other items mentioned above, some people have defended to me this item as a good one to buy for Crystal, because of the extra HP points, that tank her a bit, and the Evasion. Besides, it is an item tipically bought by supports, due to its active efect: you disarm your target, rending him unable to atack by right click (they can still use their spells).
I dont like it because:
It will be dificult for you to stand in the middle of the fight to disarm that carry without being in risk of dying too rapidly;
Your enemies will be probably getting a Black King Bar against your main source of damage, and that prevents you from using your Halberd on them;
It's an expensive item (3850 gold), which pieces give you status I really don't think are interesting for CM: 380 health - through which the carries will still cut like butter, specially if they build Monkey King Bar against the evasion; 0.6 health regeneration (no need for more HP regen, since you will by now have the Tranquil Boots and Force Staff; 25% Evasion - the only thing I really appreciate in this item for CM, but still too easy to counter (some magic disables and she's done for, some extra attacks and the evasion will not avail her, and of course, your foes can buy a Monkey King Bar); and 25 attack damage and a Maim effect on your attacks, from which you profit very little since you're not a right clicker.
This said, if you manage to save up for this item and survive long enough to use it properly, it can be awesome, specially against ranged right clickers such as Drow Ranger, Weaver or Viper.
Very similar to the Heaven's Halberd, this is a support item usually bought by heroes with more survivibility (that will therefore beneficiate from the evasion) and that use the first item that composes it, the Medalion of Courage. Even so, it can be good to build this item against a heavy lineup of right-clickers, using its active against them (30% miss change on their attacks and less armor) or to help your allies (transferring to them the 10 armor and 30% evasion that it passively gives you). Just be careful not to use it offensively if nobody else is helping you (you're giving up on the items armor and evasion and besides the miss change little does that do to your survival, since you will probably not be able to click your enemy to death just because you took his armor).
Other items worth considering
For stats and to hang on
The item that says "this game is not going well for me". And there should be no shame in it - it is a very common item even in pros. You're dying a lot, not that it is your fault, and you never have the money to do anything serious - Bracer gives you nice stats, and can later be upgraded to a Drum of Endurance.
We have already talked about this item on the "Core items" section. It is something I usually don't buy for CM, unless your enemies in lane use a lot of spells - in that case don't hesitate to stay with the Magic Stick or to go for the Magic Wand for more stats, specially if the game is going hard on you.
It grants a total of 95 health, 0.15 health regeneration, 5.7 armor, 5 attack speed, 65 mana, 0.2 mana regeneration and 5 attack damage - and when you activate it, you end up with a total 7.7 armor. All of this for 2300 gold (with the downside of costing 225 mana). As a support, you will want CM helping her team surviving. Mekans is a very good item to help on this, restoring life and mana and giving an extra armor aura. It is very good for CM herself since it gives her stats and armor, which is never too much on her, as we've talked numerous times already. The reason why I don't like it as a core item is the fact thatI prefer the cure and mana regen of the Urn of Shadows, I find the HP Regen Aura negligible for your allies (they will probably already have their own HP regen items), and since I don't buy any other mana regen items for CM the 225 mana Mekansm requires to activate cost me too much in the early game, where this item is most effective. I think it is an item more adequate for heroes that occupy a greedier position, even if only #4, and don't have mana problems, such as Viper or Lich.
Anyway, if you feel your team will beneficiate from this item in a specific game and no one else is going to buy it, buy the Buckler first, for that extra armor (and if you end up by not going for the Mekans, a Buckler is always a nice thing to have).
The follow up of the Bracer. It gives you nice stats for a cheap price, and an extra move and attack speed aura for your allies. Buying it in hard games can help you grow - and don't forget it when you're chasing or running away from an enemy.
Although I've never really compleated it with CM, I have done it with other support heroes that are experiencing too much magic damage and some people tell me it's very good on CM too. I would not advise it unless in extremely rare cases, since you will already have the HP regen from your Tranquil Boots, and would prefer the Black King Bar for its complete protection from some disables.
The logical upgrade from your Mekansm and Arcane Boots, giving your team nice buffs and heals. It's perfectly viable if you go for those two items in the early game, the reason why I think it is situational and depends on your style is the fact that I don't like to build either item in the early game, and so in the late it becomes an expensive item to be aiming for - hence also my explanation on the Mekansm as a #4 item above.
This baby gives you cheap invisibility, magic resistence and attack speed. Oh yeah. The down sides are the usual ones for these type of item: the invisibility is easily broken, the extra magic resistence won't protect you against disables and it has a very low duration, coupled with the fact that it costs a fairly ammount of mana to activate (130). Nevertheless, what an awesome new item for Crystal - you can use it against heavy magic line-ups, such as the likes of Zeus, Huskar, Queen of Pain, Leshrac, Lina or even Meepo, and try to profit from the fact that you can move invisible to set up wards and position yourself better to ulti.
Depending on your play style, you might want to stay more back spamming your spells, and Aether Lens allows you to do exactly that, with the added benefit of giving you slightly more spell damage. Not an everygame pick up, but it can help you in some situation.
Infused Raindrop: this new item is wonderful to help a hero like CM, who needs all the protection she can get for the lowest price. If you're facing heavy magical damage on the enemy team, buy one of this, and let if consume itself slowly until it disappears from itss lot. The added mana regen is always nice too.
In the Core Items section I have already explained in a succint way what these options entail. Here is some more in-depth explanation.
The Blink Dagger's blunt cost, 2250 gold, must be "paid at once", that is, it is a one-piece item. Now, everyone knows that, in a real game, in the real world, you will probably not be lucky enough to save that much money at once, without compromising your role as a support, even if just for 10 minutes or so (if you keep dying, your goal of reaching it will damage your utility items even further). Besides the blink effect, Blink Daggergives you no passive effect/stats. I have seen many good Crystal's that go Tranquil Boots --> Blink Dagger --> Black King Bar. Although this is obviously possible and uses very appropriate items for CM, they ended up very frequently with no mana to do Freezing Field during the mid to late game, because they lacked Inteligence items - so that is another thing you must account for. On the other hand, if you're playing in a party or ranked game with some type of combo or reliable initiation/follow up from your team (such as Enigma's and Tidehunter ultimates), you should instead aim for the Blink Dagger, spending some extra time away from dangerous fights and farming as possible until you get it.
Shadow Blade's parts are also expensive (1400 + 1200 gold), and besides invisibility (which is easily countered if the enemy buys some sort of invis detection), only gives you stats you're not really looking for in a CM: more Damage and more Attack Speed. Go for this item only if your team has a plan envolving invisibility to initiate ganks, and in that case don't bother upgrading it to a Silver Edge, this item is just not made for you.
Works similarly to a Blink Daggerregarding positioning, but it is not so precise and you travel less distance (it works as if someone gave you a push on your back and you jump, ending up some steps in front of your original position).
Force staffing costs mana, but that is not exactly a problem in this stage of the game.
The cooldown is higher than that of the Blink Dagger, but contrary to Blink, the moving effect is not disabled when you take damage, and can be used in allies.
Force Staff's pieces are cheaper (1000 + 900 + 350 gold), and thus easier to acquire bit by bit during the game;
Force Staff's pieces give you the stats Crystal was made to increase: Inteligence(along with some HP regen). Inteligence means more mana pool and mana regen, the core of this hero (and, if you like to think of it also this way, each 1 point increase in Inteligence on her means 1 more point in damage too, that is, 10 damage, more or less half than the Shadow Blade).
You could say that Blink Dagger is made to be used more aggressively (think of the heroes that usually buy it, such as Axe or Batrider), whereas Force Staff is an item that can allow you or yourteammate to pursue but also escape more easily in pub games.
Casters for that Crystal Maiden with money to spend
I have saved these items for last, not because I don't think they could be good choices, but because they don't suit my play style with Crystal Maiden most of the times. I consider them also too expensive for the usual CM game. Even so, they can be a good choice if you're going for a more aggressive and less supportish style, or if by accident you're the one getting all the farm in your team and they could do with a little more disable.
One of my favourite Dota2 items, the Oblivion Staffgrants everything a right clicker mage wants: Inteligence, Mana regeneration, Damage and Attack speed. Unfortunetly, Crystal Maiden is not famous for her right click prowess and lacks other things more than mana regen and damage, so I don't think this is a core item on her (note that the most expensive piece, the Quarterstaff, costs 900, to grant only exactly attack speed).
However, if you're feeling the game is giving you space to be a little more aggresive, or even if you are always left behind defending lanes, consider it, as it can help you become more that right clicker. The Orchid Malevolence is its natural extension, granting you a very handy silence for that irritating mage foe or magic damage dealer ( Storm Spirit, for instance - he can't do **** silenced).
It gives you a slow, Inteligence and more HP. Fairly interesting, although I consider Crystal Nova enough slow for CM already, specially since she doesn't have any proper follow-up on her own for this item, as let's say, a Skywrath Mage has.
Possibly, the dream item of every Inteligence hero - and support - on the game. It costs a hell lot of money and gives you 10 Strength, 10 Agility, 35 Intelligence, 150% Mana regen and an hex, very useful on the late game. However, on CM I prefer to buy the cheaper Shiva's Guard if I am on the verge of acquiring a Mystic Staff, since I rather boost her armor and find the mana regen a waste - if the team is not very eager for that hex, of course.
Emits a weakening blast that increases the magic damage enemies take, for 16 seconds. Of course this is an awesome way of taking away that magic resistence your enemies naturally have before blasting them away with your spells, but the sad truth is you have already other priorities to worry about, survivibility on top of that, so if you're being able to fully channel your ultimate your will probably prefer an Aghanim's Scepter, contrary to other heroes like Sand King or Undying (who, by the way, are awesome partners for you if they purchase this). The stats this item gives are very good (+6 Strength, +6 Agility, +6 Intelligence, +6 HP regeneration, +6 Damage, and +6 Armor), but it is situational, and has a big piece, the Helm of Iron Will, which is heavy to build and carry since it does not accomplish much per se for you.
Lifesteal from spells?! Oh yeaaah. Less cooldown on spells?! YEAAH. This is Octarine Core. Of course there had to be some kind of downer to this: it is obscenely expensive (5900 gold), with a Mystic Staff (2700 gold at once) piece in its composition. Also, you can't expect to stay alive in teamfights in a regular game just because of the spell lifesteal, since you don't have that much HP points anyway and to be fully healed you need to be sure you're causing massive magic damage (that is, you can channel your ulti without interruptions). It is therefore a very nice addition to the luxury session, helping you with the cooldown of your ulti without having to buy a stupid Refresher's Orb (since this item gives you a good chunk of +450 HP and +400 Mana on top of +25 Intelligence,+4 HP regeneration and +100% Mana regen).
The no-no items
In this section I give you my opinion on some items I think are a waste on Crystal Maiden. Like in all things in DotA2, it's a gamestyle and preferences thing, and of course you could do well in a game with some of these: but if you follow my build, don't go for them.
You have a whole skill which has the single purpose of granting all the team mana regeneration. Don't think that extra 135 mana every 55 seconds will make that much of a difference. On the other hand, if you're buying it because of the 250 mana adding to your mana pool, just wait some levels and you'll see that mana pool growing naturally - or buy some other, more useful item, that grants you Inteligence, such as a Force Staff or a Eul's Scepter of Divinity. I would even prefer you bought Power Treads, because of CM's despicable attack speed, and switch it to Inteligence when you're out of danger. Arcane doesn't help CM with her poor move speed and armor, and it becomes quickly useless as you max out your Arcane Aura.
It might seem tempting, but Crystal's not simply made to be surviving by being tanky enough. Besides the raw 1060 health points it gives, it works on percentage, and CM's max health will never be high enough to compensate the Tarrasque. Besides, in the late game your foes will have that much damage and attack speed, so if you expect to survive just because of that little bit of extra health, it's not going to happen, they will cut your extra HP like butter. Rely on your skills instead.
Or any other damage or farming item, for that matter. Radiance is an item built to farm and for those who can stay alive long enough to deal its damage over time, and CM is not that hero. Consider carefully any item that you will buy her for damage, since she was thinked as a mage magic dealer, and will not therefore benefit of rightclick power in most circumstances (nor does she have the attack speed for DPS). It is a terrible waste of money (of course if you want to go straight to Low Priority, save for that Divine Rapier...)
On the other hand, the Hand of Midas is an item that grants attack speed and is made for farming. Since you do not need the attack speed as a priority, and you're not supposed to spend time farming nor aim for the late game to transform yourself into a super carry, don't waste money on this (and yes, I know some competent players do this, but no, I don't think it is viable playing hard support since it gives you zero utility as a #5).
I will try to give you only the highlights in this section, since there are already so much good guides explaining the support role throught the game.
An excellent and summarized yet complete guide you can turn to when learning how to support is Sando's guidehere on Dota Fire.
Help your teammate survive and last hit, by harassing the enemies - use your skills or just your right click to ensure they can't get close to the creeps without losing HP;
Do not auto-attack the creeps, since it pushes your lane and that is not good for both your XP nor your teammates's last hitting, providing the enemy with easier farm under their tower (and possibly stealing last hits from your carry/core companion). However, if your intention is to push to try and take the tower as quickly as possible, then do auto-attack.
Deny your creeps, by pressing A and clicking on an allied creep close enough to death (as if you're killing it yourself). This provides the enemy with less 50% experience than if the creeps died normally, and prevents them from getting a gold reward from them. Since you will not be attacking your creeps, you can focus on denying and harrasing, though denying it can be really hard with CM's low base damage (and attack animation);
Use your consumables or buy more to use in your teammate in need;
If you are on the safe lane (Bottom Lane for Radiant and Top Lane for Dire), pull, by atracting your creeps into the forest neutral creeps around seconds 13/15 and 43/45 each minute (see here how, also for double and triple pulling);
If you can leave your carry long enough for the pulling, try to stack creep camps too: neutral creeps in the forest respawn every minute, providing there isn't anyone or anything in the camp. If you pull them out of the camp before the minute mark, and they stay out before the minute mark, new creeps will respawn and you will now have two groups of creeps in the same camp. By doing this you are helping your carry farming later.
Also, if your teammate in the safe lane can cope on his own for a bit you can jungle early so both of you have more XP for yourselves. Again in the words of T1mmay: "Killing the big creep and stacking, then killing the next big creep, gives you level 2 in just over a minute of the game. On the dire side it doesn't even take very long to run to the big camp and Frostbite the big creep, whilst being near enough to help in lane if it's required". Then, make an appearance once in a while to try and take your enemy off position, maybe scoring a kill.
If you are on the hard lane, ward the forest entrance or any other path to your backs and always be watchful for that missing heroes on the other lanes;
Call out the missing heroes on your lane (either by writing on the chat or simply by Alt-Clicking the missing enemy's photo) - let's face it, as the support you will have a game far more peaceful than that of the carrys, so it falls upon you to worry most with this type of things;
Watch out and warn of the existence of runes for your teammates, if you have vision on them (do not abandon your lane just to check on them, if you can avoid it, as it is a very dangerous situation for you);
Change lanes, even if only temporarily with TPs to go and to come back, if your teammates elsewhere are in trouble, or to help set up a gank (more on ganking and roaming here).
This is maybe the most technical thing you will have to learn playing as a support.
Always ponder where you need vision in that specific point of the game: to defend a certain area of farming for your carrys? To push on an enemy's tower?
Some places are always good to ward, such as those high marked places, or the entrance to Roshan's pit (you want to know if your enemy is trying to sneak in there).
Be attentive of where you place your wards and their "life time", in order to be able to notice your enemies' counterwarding;
Counterward yourself, trying to guess by their mouvements where the enemy has placed its wards and killing them by using Sentry Wards;
Use your wards to block your enemy's neutral creeps camps (by putting either an Observer Ward or a Sentry Ward in that camp's vision) The way I usually go about this is profiting from our team's movimentation in the enemy's jungle for a bit to clean up the camps for myself and then I usually place a Sentry Ward, if I already have vision near with a normal ward (because sentries, even being more expensive, do not have cooldown, and I want to save those Observer Wards to spot on more interesting places). This is a very interesting thing to do if your enemy team has late game farmers, as it will stop their peace-time farming in the jungle and thus make their item progression more difficult.
I recommend you this video on how to ward (and its sequels):
PPD (pro player and captain for EG) vid with a lot of different aspects related to supporting:
Purge's videos about warding, dewarding and other aspects:
Stay at the back, or on the side: far enough not to be the first one targeted, but close enough to jump in and start using your spells;
Use your Frostbite first, to disable the target your friends are trying to kill first, or Crystal Nova if he is too far running away;
Activate a Dust of Appearance or place a Sentry Ward at the beggining of the fight, if you think that invi hero is bound to make an appearance any time soon (no pun intended);
Sacrifice yourself for your carry - if you see your carry fleeing from a murderous enemy and you're near enough, trade your life for his, by using Frostbite and Crystal Nova to slow the enemy down and body-shielding your carry (physically blocking your enemies path). It is possible that your foe decides to call out on the pursuit, leaving you both alive. In the worst case scenario, he changes targets, and your carry lives. In most situations this can be an awesome play by the support, since he's not supposed to have great farm nor teammfight importance anyway, while protecting a hero whose death would be more damaging to your team as a whole;
Consider not using your ultimate in a situation where you will most likely die in 2 seconds, unless you help someone with that, because otherwise you're just spending the rather long cooldown of that powerfull spell for nothing.
Ward, do the ocasional farm and stack (as I explained above).
Never be alone unless you are: i) farming safely a creep camp (safely because you have vision or are accompanied); ii) warding (safely too, for the same reasons) - almost any ganker can finish you off quite quickly at any stage of the game if you are alone (specially if we are talking about a Slark, a Pudge, or a Spectre); iii) safely defending a lane near your tower.
Chose a place where you think your enemy has no vision of you and call your teammates to do a smoke gank, by Alt-Clicking the Smoke of Deceit in your inventory. Ensuring your enemy has no vision there is very important: don't just smoke up on the lane near enemy creeps or in somewhere they could obviously have wards, because watching a whole team suddenty disappearing will at least be a sign for concearn. Instead try to be casual about it, show yourself somewhere in a lane and then quickly encounter your friends in a safe (warded by you) corner and smoke up, then head for your enemies's jungle or Roshan's pit.
Defend your towers and push a bit the lanes, always safely (once again, if you are accompanied, have vision, or don't venture too far).
Some people asked me "what do I do when my teammates are all scattered in the map and I feel like I'm always roaming alone"? Well, I only see one option: stick to someone you think you can help in an eventual skirmish, or do the things I mentioned above - ward and stack and farm, as long you have vision over your enemies or the jungle you're in.
I laned with Bristleback in the hard lane against Lycan and Vengeful Spirit, following strictly my initial build in terms of items and abilities. Since we had no curing abilities in the team and did well from the start, I rushed my Urn of Shadows and maxed the Arcane Aura, so at level 6 I could pick my ultimate without having to worry too much with mana, and to help Bristleback excel without having to buy a Void Stone until much later in the game. The downside to this was that I only had a point in both my nuke Crystal Nova and my stun Frostbite, but it was worth it, since by that time the massive slow and damage of the Freezing Field would be useful in teamfights - all our enemies were still week to that much magic damage -, and the slow from Bristleback's Viscous Nasal Goo was sufficient in one man's situations.
I then proceeded to up my other two skills equally, starting with Crystal Nova for the extra nuke damage and extra slow duration as soon as possible - I figured that the slow in move and attack speed would help my teammates better than Frostbite, since we had already good stuns from Tiny and a lot of mobility to get the targets with the Phantom Assassin and Disruptor's Glimpse - and I gathered that our main problems would be Lycanand Templar Assassin, and to deal with them, because of their high attack rate, coupled with the Meld invisibility from Templar and extra wolf units from Lycan's Summon Wolves, AoEs help a lot.
The two other items I picked were again an echo of our worst enemies: My channeling was being stopped by the Magic Missileand Light Strike Array, while I was dying mostly at the hands of Lina, and their carrys had not yet become a problem, nor did they have much HP points or magic protection at this point. Therefore, a Black King Barwas the obvious choice for the game, since it helped me avoid all damage caused by Linaand channel my ultimate without interruptions, dealing a lot more damage with it - later, if the carrys started posing problems, I would have to think about some armor item or disable to counter them.
Since I felt the other support from my team, Disruptor, was not helping that much with the support consumables (which in this case were only the usual Observer Wards and some Dust of Appearance for Templar Assassin), I settled to buy these throughout the game and only get the usual Force Stafffor mobility - indispensable since they also had so many ways of messing with it, such as Meat Hook and Nether Swap - and save up for that BKB.
The game ended soon (it lasted only 30 minutes) and I never spent time farming, because the team was doing so well; also, I had a problem with the courier - people canceled it with my items on it for something like 10 minutes or more, something that happens all the time to poor supports - so my BKB and its pieces didn't really helped me in time, but in the case our enemies would do an unexpected turn of events, I was prepared to deal better with them with it by then.
As to my gameplay: I sticked to my lane as much as possible in the early game, since it was not safe to wonder around at all times with a Pudge on the other team and with my lane partner I had the chance to do some kills, whereas he alone could suffer too much harass. When alone against Vengeful Spirit, I would only be in range of the XP, very close to my tower, and dealing some light harrass on her when possible, because her combo damage could easily finish me off if I wasn't careful enough. When teammfights around the map started to happen, I tried to always be with the team for this events, while only wandering a bit when I wanted to ward. Again, it was not a safe game for a CM to be wondering alone, since an encounter with any of the enemy heroes could easily result in my death.
Ended up with a final 11-7-26: Died more than our carrys but not so much that I feeded theirs, which is perfect, while the deaths were compensated by more kills than deaths - but not at the cost of stealing last hits from the carrys, all of which killed more than me. Lastly, the number of assists, the higher in the game, shows the essential: I was there when things happened, I helped, but I did not ks. I would say you could aim to do such an end panel with your Crystal (and for that matter, any support).
Also, if he had done this, since his mana pool was already well provided for with the Force Staff, he would not have experienced mana problems as he did, for instance, in the long battle against Shadow Fiend;
He opted to max out his stats for survivibility instead of maxing out the Arcane Aura and Frostbite, when he already had what I call the "basic CM survival kit": Urn of Shadows + Force Staff, and the extra stats didn't really do anything for him;
He tried to use his Urn of Shadows offensively with no success, which happens in most cases with Crystal unless the enemy hangs by very few HP points. Usually you will not want to use the Urn offensively with Crystal because heroes either die near you or definitely escape, since you don't have any follow up and can't really profit from disabling their Blink Dagger's as, for instance, a Pudge would, and you need the charges to use defensively much more often.
His final item choice, the Eul's Scepter of Divinity, was a good choice when considering surviving against his enemies in teamfights 5 vs 5, but it was not the best choice, as it was proven in the last minutes of the game - if he had worked towards a Black King Bar, he would have prevented the disables from Earth Shaker, Drow Ranger and Witch Doctor, as well as the magic damage done by Shadow Fiend's razes. Moreover, Purge was tempted to buy the Eul exactly because he was feeling some lack of mana - most people that play CM and don't max out her aura feel this too, as I explained in the item section.
Crystal Maiden has another thing I love: she is welcomed in almost every team, since she is a complete support to have in most situations, and can adjust accordingly. Below see heroes that benefit from her more than usual, and the possible combos.
One of my favourite combos with Crystal Maiden, Bristleback not only really benefits from the extra mana regen, being able to Quill Spray at will, but also makes good use of another slow and a stun, to help with those early kills. Together, they can easily win a lane and mess a lot with the enemy team in the early to mid game, creating space for the carrys.
These two are the most famous combo lanes with Crystal. Juggernaut: she slows and stuns, while he uses his Blade Fury. Most heroes will not be able to resist this damage. Furthermore, what's so cool about this combo is that it works even if your enemy is already aware of it - what can he do, stay far away and safe but with less XP and last hits? - and the abilities of both heroes can be used many times due to the low cooldown, and the mana regen provided by CM.
Ursa is another hero that really can benefit from a stun + slow to fully use her Overpower on enemies - if Crystal can make them stand still a bit, Ursa can finish them off quickly.
A special mention must go out to an unusual hero, Undying, with which Crystal can wreck havoc starting from level 2. If Undying does two succeful double Decays followed by a Tombstone at the same time you nuke with Crystal Nova and Frostbite, someone is dead, even if it is an extremely mobile hero (if it is someone not so mobile you can skip the Frostbite and directly start to max out Crystal Nova and Arcane Aura). The reason why this duo works out so well is that most people forget both heroes are specially dangerous in the early games, and Crystal has all an Undyingneeds: a slow + nuke, a stun-like ability, and lots of mana regen for him to spam his Decayand Soul Rip. When you hit level 6 it's even worse, because your Freezing Field will also damage and slow so much that the zombies can pick up everything that's left. If one of you manages to build up a Veil of Discord and use it properly before their Black King Bars pop up... BOOM!
Any hero that really profits from mana regen will be grateful to have Crystal as an ally, since it will allow him to spam at will, making them more dangerous without as much mana regen items. That includes the likes of Storm Spirit and Zeus, for instance.
Since CM's ultimate is so difficult to use in most cases, any hero that helps her with that can result in a great teamfight combo: Enigma, Magnus, Dark Seer, Tidehunter, Winter Wyvern and even Faceless Void (if he manages to let CM out of it and it catches enemy heroes on their margins) can help set up the perfect conditions for Crystal to channel her ultimate around a larger number of enemies and with less risk of being interrupted.
Being so fragile, almost everybody will be a difficult enemy for CM, specially if the players know her well enough. Even so, some are worse than others.
Anyone with a silence will present problems, since she heavely relies on her spells to get by. Those include Silencer, Drow Ranger and Riki, but also anyone who will likely purchase an Orchid Malevolence ( Clinkz, Storm Spirit).
These two, however, deserve a special mention: Silencer impersonates everything you hate, stealing you Inteligence, burning mana and silencing you forever (players usually go for the Refresher Orb), plus having a really damaging right click for an Inteligence Hero. Doom, on the other hand, can doom you to oblivion, not only interrumpting your ultimate and silencing you, but also dealing you tons of damage, specially if he buys the Aghs (increased duration). The good news: most Dooms will not silence you but opt on going for the carry. Otherwise, how can you deal with being silenced? You simply will have to try and stay alive until their abilities are used, avoiding being the first one spotted. Or rush that BKB, if the silence in question does not pass it (the silence from both Silencer and Doom pass).
Lina, Lion, Tiny, Queen of Pain, Zeus: Heroes with high burst damage or powerfull damaging combos such as these will kill you so quickly you will end up deeply frustrated. The best you can do against them is: guess their moves before they do them. If you want to avoid being toss-stunned or blink-screemed ward the map accordingly, and don't be deceived if you see an enemy hero alone.
The ultimate combo heroes against you. Spirit Breakerspots you defending that tower alone, he's gonna charge, and you're dead. His combination of damage spells, along with his passive stuns, will make it impossible for you to just try to frostbite and run, or try to ulti. When this guy is playing against you, I would advise you to try never be visibly alone in the map.
Same can be said about Pudge. If he sucessfuly hooks and dismembers you, there is little chance you could escape him alive. That said, Force Staff can be a powerfull ally against him, as long as you don't try to kill him (don't attempt it, he's got all that extra fat from his passive Flesh Heap) and simply run. Better than that: keep your eyes open for his location at all times, don't expose yourself alone when he is missing, and buy a lot of Observer Wards to counter him. Also, this is valid for any other heroes with strong ganking potential, such as Slark, Storm Spirit and Clinkz.
His name says it all. He will attack you quickly and furiously, burning your mana to the point of ending your life with his Mana Void. If you try to resist, know he has an extra 50% magic damage resistance because of his passive ability. Run, run now! Just kidding. A good way to try to escape him would be, as difficult as that seems, not to cast any spell at all, ensuring that way that he can't kill you with his ultimate, or try to only Frostbitehim and run(your ultimate spends too much mana and he can easily escape it with his blink or kill you first).
Nyx Assassin and Bounty Hunter, If played correctly, these two will mean trouble, as they will sneak up on you first, invisible, stun you and then finish you off - either with the simple right click damage offered by Jinada, or with Mana Burn. The best you can do against them is pre-setting that defence Sentry Wards, so you will know they are coming.
The same is not true concerning Riki and Clinkz, because although they have invisibility to start attacking you unnoticed, you only have to Force Staff yourself away from them and use your skills if they come after you to try and survive - they don't naturally have any disables other than their silences/slows.
Tips to counter invisible foes
Decide consciously on whether you need Sentry Ward, Dust of Appearance or both. If the enemy is permanently invisible ( Riki), you know he is at that area permanently ( Broodmother - watch for the webs) or you want to prevent a gank on you when defending somewhere alone, buy sentries. If you need to pursue an enemy that often uses his abilities to stay alive on the spot ( Sand King or Templar Assassin) or to run away (anyone with a Shadow Blade and other invi heroes), don't pass out on Dust, cause it will be more efficient (you should prefer a visible running enemy to a running visible-only-on-the-sentry-area enemy).
Because most times you don't really now what is your enemy's style, and he may combine it with other invis on the same team, and also because Dust of Appearance has a use cooldown (30 seconds), I would advise you to purchase both detections, even if it means occupying two slots with the same problem. It will be worth it.
Spend the entire game with invis detection items on your inventory. Once again, it will be worth it.
Share your invis detection with your teammates. For instance, if the game begins and you realize the invis foe is pissing out everybody on another lane, you may want to TP there to give a hand and a Sentry Ward. Or just buy the sentries and drop them from your stash or put them on the Courier for your friends to get them.
Everytime a fight is sure to happen, place a sentry on its hedges or in the center of it. That invisible enemy is going to be around sooner or later.
By some reason, you know your invisible enemy is just in front of you - either because he run there in a straight line, or because we're talking about a Templar Assassin, Sand King and his Sand Storm, or holder of only a Shadow Amulet. He has low health and could easily die, but you and your teammates have no way to make him visible: use your AoE abilities, Crystal Nova and Freezing Field, that way securing a kill (but not stealing one - if you have some kind of detection use it and let your teammates finish off the enemy).
I repeat, THAT BASTARD. The simple fact that he exists will make you waste all your money on wards, and if by any chance you happen to step on those mines... Well, you're ****ed. They deal a high mix of physical and magical damage, depending on the mine type, which will difficult your protection strategy. A well played Techies will be so dangerous to you as a CM that I decided to prepare the special "make him pay!" tips bellow!
Tips to counter Techies (there can never be enough of these)
The game begins. If possible, don't go for the first bounty runes without carrying two Sentry Wards with you to put on the predictable path everyone uses to get them (for Radiant and Dire both paths that pass through the Secret Shop, or the forest entrance) and near the rune spot itself. If you do this and see no bombs, come back to the lane by the exact same path you used to get there. It may seem like too much, but a skilled Techies kills Crystal Maiden at level 1 with the proper placing of only two bombs (and players usually TP out before the game begins to set those up). Of course that, if you have seen the bombs and destroyed them or they exploded somewhere else you don't need to be this much careful, because it will take time and map displacement for Techies to prepare another CM cementery. Usually, however, Techies will teleport to a lane and set bombs near the Secret Shop and the paths used by heroes but not by creeps.
Once again on the lane, without news of any bombs exploding somewhere else, don't step nowhere your creeps haven't been first. That means no entering the Secret Shop nor woods, until you can be sure (by sentries) that they are not mined. As soon as you can be sure of that, place an Observer Wardon the woods where Techies will likely be hangin', to watch for his movements.
Tank yourself up: armor and strenght items such as Ring of Protection, Gauntlets of Strenght, Bracer and Magic Wand are welcome in this stage of the game, when Techies has to rely on his physical damage from the Land Mines and his suicide ability.
The rest of the game you just have to repeat this initial care: prefer traveling by Town Portal Scrollfrom lane to lane to walking there by foot.
Ask a more tanky teammate to help you ward or scout out in places you think Techies mined (most Strength heroes are relatively tanky and have more chances of surviving). Some teammates are specially good for this job: Abaddon, because the bombs will trigger his ultimate and he will not die; heroes with walking minions (flying minions don't trigger bombs) or illusions, that can send them to scout the map ( Nature's Prophet, Broodmother, Lycan, Naga Siren, Terror Blade, etc.), and heroes with some sort of spell that allows you to scout high ground (such as Powershot, Ice Vortex). Dont' forget your own Crystal Novaprovides 900 radius ground vision at the target area for 6 seconds, so if you want to ward highground use it for vision before crossing!
Try to antecipate Techies' moves with the Observer Wards, so you will know where to expect bombs and try to gank him (not alone, because his Suicide Squad, Attack! ability will quickly finish you off).
There are some places that are just too good to be left alone by him, such as your secret shop, the entrance to your woods, Roshan's pit, neutral camps and near any next tower you will be targeting. Use the above mentioned strategies to prevent getting killed on these places.
When pushing a lane without a Gem of True Sight, suggest to your teammates not to advance all joined together and at the same time, but instead the tankiest in front, carrying and placing Sentry Wards along the path.
Decide with your team on the medium to late game if a Gem of True Sightis needed, and buy it for your team, if you have the money and you're doing a favor to the carrys in need. That said, don't carry it on you NEVER, as you are the hero must likely to die at any moment and can thus lose the money invested and provide the enemy team with a free wards detector.
Having the Gem of True Sight on your side of the team, let the tankiest teammate carry it in front of all of you when you want to teamfight or push a tower, and be near him to destroy the bombs in sight with your range. To push places where you have no vision (elevated places or because it is night with less vision), don't go in before the creep wave, or use one of the spells I mentioned that gives ground vision ( Crystal Nova, Powershot, Ice Vortex), to help you see if there are bombs or not (even if they are Techies'ultimate, that is, they will not explode automatically but creeps will give you vision on them on the highground). If you just step up into highground with the gem, you may be sitting into an evil nest of Remote Mines you will only see too late.
If you have to live with the fact that bombs will be bombs and you can't prevent them, consider getting more armor (specially for the beggining of the game) and/or magic resistence (as the game progresses Techies will be using more his Remote Mines, specially to protect their structures, and they deal magic damage instead of physical damage). Both armor and a Black King Bar go very well on my preferred build, as you have noticed on the Item Build section, and although I've rarely tried or seen a Cloak/ Hood of Defiance/ Pipe of Insight type of defense on a Crystal Maiden, I can't say it will be a bad idea for sure (but don't rely on these, and conform to the fact that probably you will need the money for other items).
Stay as far away as possible of Techies. And I mean it literally, meters away. His Suicide Squad, Attack! deals 1150 physical damage (before reductions) alone, so you wouldn't won't to be caught close enough to be exchaging hits with him until he decides your HP is sufficiently low for his suicide.
Stay as far away as possible of Techies, unless you are accompanied and he is alone. In that case, don't hesitate on going after him, if you're sure that he hadn't had the time to place mines beforehand and is trapping you. As a roaming hero, he will very often be spotted alone along the river or on the forest mining, and if you can catch him offguard on those moments you can easily kill him (with help, of course), since he has no real escape mecanism and has low HP. Even if you force him to simply suicide, it will be worth it, because of that extra time without bombs you buy for your team.
I have good news: Crystal Maiden is herself a counterpick of sorts against the following heroes, excelling in the match up against them! Of course this doesn't mean she can man-fight them in any circumstances or something like that - don't forget she's just a fragile lady with loads of magic on her side.
Yup, the big scary carry Phantom Assassincan just be blown to pieces by your spells until she has a Black King Bar (so until then try to play it aggresively - not suicidally, mind you - against her). After that, buy a Ghost Scepter and save it for when she comes jumping into you. She will either wait to attack you or attack the next nearest victim: Force Staff or Blink Dagger yourself away during that time and you should be fine, or even attack her too if her BKB is down and you're feeling confident.
The same is true against any other carry that is squishy in the early game and does not have protection from magical damage, such as Ursa or Troll Warlord. If you manage not to be caught too out of position, and they don't have a big XP/farm advantage over you (nor a Black King Bar or a Skull Basher either), you can Frostbite them, followed by Freezing Field and then Crystal Nova to finish. Assuming, of course, they don't have a big advantage over you that allows them to simply right click you quick enough. The fact that she can't solo kill these heroes doesn't mean that she doesn't counter them; the beauty to it is that Crystal Maiden can be useful even in the late game when they are scary, if she manages to position herself correctly and buy the right items (items like Ghost Scepter and Force Staff or Eul's Scepter of Divinity, that help her survive until the BKB's are down again and you can re-enter the fight).
I don't know if it is their affinity to trees and the fact that these don't cope well with ice, but the truth is you can face-up to both these heroes with ease in most cases - if, as we've said already in so many cases, they don't have an off-cooldown Black King Bar and too much XP/farm advantage over you.
Nature's Prophet usually doesn't buy a BKB, and relies on his trees and right click to melt waves and towers, protected only by mobility/escaping items. If you sneak up on him and disable his escapes with a quick Crystal Nova or Dust of Appearance before he escapes, you can proceed to channel Freezing Fieldright beside him, so he takes full damage. Don't be scared by the physical proximity: there is nothing he can do about it, besides trying to kill you before you kill him with his rick clicks, or teleport anywhere else before dying, and in that case you hang on until the last possible moment and cancel his TP with Frostbite, finishing him up with right-clicks.
Treant Protector, on the other hand, usually relies too much in his invisibility plus damage block and HP regen from Living Armor to walk around unnoticed setting up ganks and wards. You should have properly spread out Sentry Wards and Dust of Appereance, you see him, same combo: sneak in right besides him as if you didn't see him, Frostbite into Freezing Field, and his Living Armor won't avail him because it will be dispelled by the damage instances taken. As he can still use Overgrowth only to escape him, this works out better if you know it is on cooldown or if you're with another teammate that can help following up your initial disable. Even so, don't worry if you've used your ultimate and made him have to use his to escape alive; your cooldown's are similar, and you basically just forced your enemies to rethink their next teamfight strategy, since they cannot count on the AoE disable from Treant in the next 70 seconds.
My personal favourite popsicle is the Dota Shelob, Miss Broodmother. Someway they always seem to underestimate the fact that Crystal Maiden has two very strong AoEs and is supposed to always carry vision items with her around... The trick is to lane against her first of all, making sure you harrass her out of last hits and kill her spiderlings with a Crystal Nova maxed asap, while cautiously maintaining your safety distance. Then, proceed to kill her by planting vision, pretending you don't see her to get up close and personal, and doing your Frostbiteinto Freezing Field. By level 6 this should be enough to finish her off, and you can proceed to do this until she has a Black King Bar or an Orchid Malevolence.
Don't ever try this if she is too much ahed of you or the game is very late, of course, as she can just right-click you to death quickly with her Insatiable Hunger on. If you shut her down heavily in the early game, however, her core items and utility will be delayed in a very favourable way for your team.
Don't forget to use your AoE's under the pressure of having just lost vision of an almost dead spider you know it's there, it's so exhilaranting to get those hunch kills.
To sum up
I don't like to think in terms of "when to pick/not to pick" CM, because in reality in most pub games you won't get to be that picky: your teammates will not want to agree on who to pick nor will they want to compromise, and the other team will wait until the game starts and then pause for counterpicking. Also, in more competitive games the supports are pretty flexible and you will want to be picking first so your cores aren't counterpicked. Therefore,you can manage either by instantly picking Crystal Maiden if you're feeling like playing her, and then deal with her foes if they pick them, or wait until the last minute and opt not to pick her only if you see a lineup that will definitely **** up your game (something in the lines of a Silencer plus Spirit Breaker plus Anti-Mage plus Nyx Assassin and Pudge...)
Just follow your heart. In the end, it is your ability to play her better than your opponents play their heroes that counts, since there is a solution behind every counterpick.
This may seem counterintuitive, but remember what philosophers say: you must think counter arguments, if you really whish to improve on your own :)
If your facing a specially annoying Crystal Maiden, consider the following tips:
Focus her first in teamfights. Being so squishy, she will quickly die and then you can deal more easily with your other more important enemies, without being stunned, slowed or heavily damaged meanwhile.
Buy a Black King Bar. Watch her horror when she tries to repel you and alas!, can do nothing if you're not affected by her spells (even her ultimate can be stopped with BKB, and all her abilities deal magic damage);
Keep an eye(and an Observer Ward) on those common spots such as passages to the river and the entrance to Roshan's pit. She will probably pass there sooner or later, warding, and if she is alone this is an excellent time to kill her in a second and move on, since she can't usually resist alone against a gank.
Don't underestimate her, specially if she is channeling her ultimate. It really gives a lot of damage and slow, so the best you can do against it is to decide between: Interrupt her channeling (if you can do this, don't hesitate), try to kill her with your right click before she kills you or run away from her AoE as quickly as possible.
If you are the Crystal Maiden affected by these countertips, don't forget the following:
Try to stay at the back of teamfights, close but not visible nor vulnerable against the initiators;
Don't walk around the map alone, specially if there are known gankers out there. Ask your teammates to accompany you when you need to ward;
If you notice someone has purchased a Black King Bar and is invulnerable against you because of it, try to focus someone else and avoid the BKB holder until after he uses it (as the game goes on, its charges will quickly fade to the mere 5 seconds).
I would say that the most important lesson you should learn when playing Crystal Maiden is to play for the team. That can really be the difference between winning and losing, noticeable more in this hero than in most others. As someone on Dota Fire put it, you have to give in to your motherly instincts :D
Crystal Maiden is indeed a really fun hero to play. I hope this guide has helped you learn something that will benefit your games, bearig in mind that final purpose: fun.