I am writing this guide to help a few friends of mine who recently started playing get a better grasp of the mechanics, heroes, and overall play style of DotA 2. This is in no way an end-all be-all beginner tutorial, but a few things that I think are very important to know when playing the game.
My name is Denoray. I have been playing DotA for many years now, dating way back to the original in Warcraft 3. I started playing around 10 years ago, focusing mostly on the MOBA genre in WC3 custom games, but my favorite game to play was DotA. I participated in amateur tournaments on the team Toss in Tidehunter (we did around 10 tournaments, placed in 2 of them) so I wouldn't call myself an expert, but I figure what knowledge I have is somewhat valuable.
Keep in mind, I will only be giving brief explanations. My assumption is that you either have your Dota client open to reference the library, or you have a somewhat basic understanding of some of the terms/abilities/item functions. These are heroes that I feel work well with most team comps, and are easy/fun to learn.
I feel that every team should have a certain makeup to it (of course there are exceptions, but I feel there is a certain meta that is generally safe to use). That meta consists of at least one Initiate, Support, and Carry. The other two can be filled by any roll.
An initiator is a character that has a build that is great for starting a team fight.
A few introductory heroes include Earthshaker, Tidehunter, Enigma, and so on.
Earthshaker is, in my opinion, the most basic initiator there is. His ultimate is amazing way to begin a fight: simply use a blink dagger to get into the center of the enemy team, hit R, and start using your other abilities to chain stun thanks to Aftershock. However, after you use Echo Slam, be careful where you aim Fissure or you could do more harm than intended.
Tidehunter is the next best thing to Earthshaker, and in some situations an even better support. TH's ult is a massive AoE stun that does a decent amount of damage. The special part about Tidehunter's ultimate Ravage is that it is Superior Magic. Superior Magic means that the effect will persist through magic immunity. The same principle of initiation applies with Tidehunter as it does Earthshaker; blink in, hit R, use Anchor Smash on as many of the enemy team as you can hit, or at least the carry.
A supporting character is anyone that puts all of their effort into helping the team achieve victory. Their abilities focus on healing, crowd control, and other utility. Supports generally want to keep their focus on warding the map in combination with their other jobs. A few introductory heroes include Crystal Maiden, Dazzle, Lich, and so on.
Crystal Maiden is a very common support to choose for any team composition. The reason she is classified as support is due to her kit being great at crowd control with Crystal Nova, Frostbite, and her being an intelligence hero. Intelligence heroes typically scale well without items allowing them to buy wards, the courier, and other support items without the fear of being useless.
Dazzle is an example of a hero that is completely based around the role of support. While Dazzle has 2 abilities that deal damage, Shadow Wave and Poison Touch, their utility is the main reason they are useful. Dazzle's W Shallow Grave is an ability that prevents the target from dying until the buff expires. This means if you cast it on your carry they can be reduced to 1 hp, but will not die until the spell is over allowing them to get in a lot of extra damage.
A carry is exactly what their name means, someone who can put a team on their back and mow down their opponents with brute force. The role of a carry is mainly to deal as much damage as possible during a team fight. Typically, carries try to cut down the weaker enemies quickly so that it's easier to deal with the beefy characters with the help of their team. As with most carries, your job early to mid game is to farm as much as humanly possible to get a good item set for fighting. A few introductory heroes include Anti-Mage, Phantom Assassin, Wraith King, and so on.
Anti-Mage is one of the most popular carries in the game. With Blink he can farm anywhere he wants with the knowledge that if things get dicey he can leave in a hurry. With Mana Break he can quickly deplete a low mana pool hero, or combat a mage until they are either dead or low enough to use Mana Void on.
Phantom Assassin is another very common carry. She functions similarly to Anti-Mage, but has a higher focus on critical strikes and attack speed. There are certain items that are almost always must buys for carries such as Battle Fury or Black King Bar, which I will explain in the following section.
Items are a core feature of this game, and can make or break your game depending on what you choose. While I am not going to display full blown builds, I want to talk about some items I feel are necessary to learn in Dota 2.
My personal favorite item is Force Staff. This item is so versatile I get it on almost every intelligence hero I play! It can even be useful on some strength and agility heroes as well. Force Staff gives a moderate boost to intelligence and HP regen, but its real use is the activate. This item serves a wide variety of uses such as propelling yourself, a teammate, or even an enemy into a more favorable position. Force Staff can be used to push yourself over cliffs, out of Smoke Screen, and many other sticky situations.
Ring of Basilius gets a special mention due to its aura. Items such as this have an aura that benefits heroes as well as creeps. While this is nice for pushing, if you are trying to farm I recommend toggling it off so you do not unintentionally push.
Helm of the Dominator is a great item to get on ranged carries such as Luna or Mirana. While the biggest reason to get this item is its life steal, do not ignore its on use ability. With a little practice, controlling a minion for a stun or snare can lead to many easy kills.
Blink Dagger is an extremely valuable item. Almost all initiators will want to pick this up as their first item in order to get perfect positioning for team fights. There are certain combinations such as Eul's Scepter of Divinity + Blink Dagger to make some amazing escapes, but those are better left for when you have a better understanding of the game.
Mekansm is the premiere item when it comes to what a support should buy. The on use is so pivotal in a team fight I would go so far as to say it wins a vast majority of them. There should always be a Mekansm on your team. Another solid item for supports is Pipe of Insight. While similar to Mekansm, the Pipe is purely centered around reducing magic damage.
Observer Ward is an extremely important part of every game of DotA. Vision is, in most cases, the win/lose factor to many games. There are certain areas that should always be warded such as one of the two spawn points for runes in the river, and the jungles. Keeping constant vision up allows you to see incoming ganks, set up ganks, or just have overall map control. Typically towards mid game you should double up your wards with Sentry Ward to counter your opponents vision. I will provide a link to a video I found useful in teaching how to ward.
Game flow, which I will also call lane responsibility, can be a bit confusing at times. What I mean by lane responsibility is what you should be doing in lane depending on who you chose.
Mid lane will always be a solo lane in which you are 1v1 against your opponent. Very rarely will you see early ganks on mid lane as they tend to be the ones ganking. There are certain heroes that are stronger in mid lane than others such as Storm Spirit Death Prophet and Invoker. Their strength comes from either needing solo experience to gain levels quicker, their need to get all of the last hits for gold, or they have very good harassment capabilities to deny their opponent a good start.
The middle laner should be focusing on the runes that spawn at set locations in the river every 2 minutes of the game. These runes are very powerful buffs that can allow you to easily gank or quickly regenerate your resources to continue your lane phase. A ward should be placed at one of the spawn locations for the runes, and it is your job to keep tabs on them so your opponent doesn't gain control of them to wipe out your lanes. It is very common for middle lane to pick up a Bottle in order to stay mid as long as possible.
Most of the time, middle lane should be looking to gank once a rune is picked up. If you miss a rune but see your opponent get one and head to another lane, you should typically follow, unless you are unable to for some reason. Be sure to warn the lane that is in danger of the incoming gank as well. There are some exceptions to the rule of ganking though. Death Prophet is an exceptional pusher and her job is to shove down the middle lane as fast as possible in order to end the laning phase. Even though pushers like Death Prophet wont gank as often as, say Queen of Pain, that does not mean that you should ignore runes.
Side lanes are typically made up of two teammates unless there is a jungler in which case the solo lane is referred to as a safe lane. Side lanes usually involve the support on your team so they can ward without worrying about the lane being pushed down while they are gone. It is common to pair CC heavy heroes together in the duo lane in order to secure kills such as Sven and Sand King. Other common pairs are Crystal Maiden and Juggernaut, Omniknight and pretty much any carry, as well as Bane and Mirana.
The safe lane is the solo lane opposite of your jungle, and is pretty much only occupied by heroes that can farm safely such as Clinkz or Windranger. If you are the safelaner your job is typically to farm, avoid losing your tower, and avoid death as much as possible.
The jungle in Dota 2 seems intimidating, but once you learn the ins and outs of it you will be fine. Typical junglers are Enigma, Nature's Prophet, and Lone Druid. There is a lot to cover jungle wise so I will just include a video I think covers all of the basics.