So you want to sneak up lone heroes and destroy them? Do you enjoy making the enemy team feel helpless when they're alone? Are you fond of dominating pubs? Well then, Riki Maru might just be the invisible mouse for you.
Riki has gone though his ups and downs in the last few updates--from being godly overpowered in 6.85, to be completely useless in 6.86. A few buffs and items in the most recent patch have made him viable again as a mid-game carry who pretty much controls the entire map from minutes 20-45. After that he falls off a bit to more traditional hard carries. Still, after experimenting with 20 games and an 80% win rate, this is the new go-to build for Riki Maru.
This build is available on the SteamCommunity and in your in-game hero-build menus. Just look for the "Invisible Murder Mouse"
Smoke Screen This is one of the most interesting utility skills in your kit. It's an AOE slow and silence that also adds an evasion chance to you and your allies. Thrown down in the middle of a team fight it can shutdown an enemy team. When you are ganking a lone enemy you force them to turn their back on you and run out of it. On lone ganks, start with a single backstab, then drop the cloud. Max this skill last, but get a utility point at level 3 or 4.
Blink Strike This is a short range teleport with a bit of bonus damage. You can use it to escape a sticky situation by teleporting to an ally or a creep or to chase down someone who is escaping. Get one utility point at level two and max this second.
Cloak and Dagger Riki's signature skill lets him do two basic things--fade into invisibility and backstab for insane amounts of damage. This skill is ridiculously powerful now. In previous patches it was split into two different skills--one for invisibility and one for damage. Now you get both at once. This is vital to your ability to get early kills, last hits, as an escape, ganking...you name it. It's Riki's soul. Max it first.
Tricks of the Trade Riki phases out of existence and starts backstabbing everyone in a large area of effect once every second. It has many uses: it can act as an extra blink strike on a single target, to escape incoming attacks, or just an AOE murder-fest if the whole enemy team is present. It's channeled, so casting or moving will cancel the spell. However, when phased out of existence you can't take damage, dust can't find you, and you can even backstab through [Chronosphere] if you get it off early enough. If you find yourself in a tight spot simply ult and wait for an opportunity to [blink strike] away to a creep or ally. Along with everything else in his kit, this helps make Riki exceedingly difficult to kill. It's on a low cool down so feel free to use it liberally.
Forget every guide you've seen on Riki before: you're going to want to start the game with a Headdress and an Iron Branch. At 3 regen per second for you and your support the Headdress provides the equivalent of a half-tango (4.1 with your base regen) and will keep you both alive for the entire laning stage. The downside of the headdress is that it pushes the wave slightly forward to the enemy tower, but you can offset this by denying enemy creeps with your backstab.
Next you build basic gear: get an Orb of Venom if you think you might be able to get an early kill. Then build Magic Wand and finish off the early build with Phase Boots. Wait a minute. Did this guy just say Phase Boots? Doesn't Riki want agility for his backstab? Well, yes he does. Sort of.
If you do the math switching to agility on Power Treads makes backstab do an additional 22 damage as well as gives him a pretty decent +30 attack speed. Meanwhile, Phase Boots give +24 damage and an active that helps him chase down prey. As a ganking hero, the Phase boots offer much better killing potential and sets you up nicely for A Delicate Flower's patented 5 guaranteed backstab combo.
Welcome to mid game where Riki really comes into his own. You've picked up all your early items by around minute 11 and are ready to build your first core item. Most guides say you should build Diffusal Blade first. It's not a bad idea, but there's another item that will get you more kills, is cheaper, and will set you up for my trademarked signature move that you'll read about in the next section.
The first thing you're going to buy is Echo Sabre. You should try to have it complete between mins 16-18, which shouldn't be too hard to accomplish since your backstab makes farming creeps fairly easy. Once you have this delicious item go out and start ganking every lone hero on the map. Only the most tanky people will survive. With the extra gold start building the Diffusal Blade so you can get a huge buff to your agility and will allow you to slow your targets and dispel the occasional Dust of Appearance.
Finish your core build with Vladamir's Offering which will give you solid passive regen, lifesteal and a little-talked about 15% damage buff to all of your attacks. It is also useful for hanging around fights and adding an aura buff to all your teammates while you wait for your perfect moment to appear and clean up.
The one caveat to rushing Echo Sabre is if the other team has a Slardar or a Bounty Hunter. In this case, since you will need to purge their detection quickly, I suggest going Diffusal Blade first and skipping Echo entirely. Instead build Diffusal Blade into Sange and Yasha for more durability.
Echo Sabre is the reason Riki is relevant again. The item gives you two free attacks (which in Riki's case are backstabs) as well as a short 100% slow which works pretty similar to the bash from Skull Basher at just a fraction of the price. Once you have this item you can pretty much guarantee 5-7 backstabs on any lone target. Even if they dust you. Even if they cast spells to counter you. This is simply the strongest ganking maneuver in Dota at the moment. Here's how it works:
1) Locate a lone target who doesn't have any friend who will be able to get to him for at least 10 seconds. Usually this is somewhere in a lane or the jungle. Once you've found them, set up for a backstab and begin the murder. The first attack will give you your first 2 backstabs.
2)Immediately follow up by casting your ultimate Tricks of the Trade. You are invulnerable while phased out of existence and their only option is to leave your AOE or keep taking hits. Depending on how quick they are, this will guarantee you 1-2 more backstabs.
3) As soon as they are out of your AOE select Blink Strike for an additional backstab and +120 damage. As soon as you've cast blink follow up with a Smoke Screen so they can't cast spells.
4) Activate your phase boots to chase them down for an additional 2 backstabs because Echo Sabre is probably back online.
This murder routine has given you between 6-7 free backstabs before your opponent even has a chance to try to counter you. It's enough to kill all but the tankiest heroes at minute 20. At approximately 200 damage per backstab at this point in the game this combo dishes out between 1120 - 1520 total physical damage and will only get stronger as you get more items and scale more damage with your Diffusal Blade and other items.
Riki is a situational pickup which is only easily countered by solid teamwork and support on the other side. Unfortunately, as you snowball into an invisible murder mouse, many teams start working together. Your goal as Riki is to secure enough space for your team's true hard carry to get farmed enough that the other team's detect and destroy strategy is too little, too late.
The only time that I lose Riki games these days is when my team makes the terrible error of also choosing characters that depend on invisibility. If two or three people on your side have opted for Shadow Blade strategies, or, even worse, they picked Bounty Hunter, Nyx Assassin, Mirana or Clinkz then the other team has much more incentive to start investing in detection early. And every ward, mote of dust and gem they purchase is an effective counter to your whole team.
However, if you are the only invisible hero on your team then you pretty much guarantee victory. They have to invest in detection for just one hero, which weakens their ability to counter your true hard carry.
There are only a few actual counters to Riki that the opposing team can pick. Here they are:
Zeus - his lightning always seems to reveal you. This can be a huge problem.
Bloodseeker - His passive ability Thirst reveals you when you most need to be invisible.
Spirit Breaker can charge you from anywhere on the map. While charging he essential tracks you and makes you quite vulnerable to dying.
Bounty Hunter and Slardar both have tracking abilities. However, in both of these cases the heroes need to see you when you're visible to land their spell. It you catch them alone they are both vulnerable to the 7 backstab strategy. Also, when the enemy team has these guys, they sometimes feel that they don't need to spend money on wards. That's a big mistake, because they never end up landing their track.
Lifestealer - can infest you and all of a sudden a one person gank is an explosive murderfest.
Zeus reveals wards and can globally ult to help in ganks.
Spirit Breaker the same thing that makes him a counter to you helps murder opponents.
Pudge and you can hang out together and kill people after hook. It's fun.