Phantom Assassin
Recently I've been trying to climb into the top 100 PA players on dotabuff. Right now the highest I've gotten is 588th, but in my time getting there I've learned a few advanced mechanics and non-traditional item builds.
Knowing what role you're playing is the first decision you'll want to make. I personally think that with changes to PA's blur (essentially making her ganks go unseen on the minimap) PA fits best into a 2 or a 3 position. If built right, PA can be extremely effective in the early/mid game - a big departure from her previous position as a late-online position 1 hero. PA is definitely viable in any of the 1-3 positions though, but how you play her will be drastically different. In this guide I'll aim to show you how to play each style.
Item build
I studyied a lot of the dotabuff top 100 PA players' item builds. Specifically, I looked at players who had diverse builds between matches. This way I could see how different item builds did against other ones, without the player being an influencing factor. By looking at the items used and their win rates for these players I found that three items in particular contributed to an extremely high win rate on PA: Medallion of Courage, Manta Style, and Desolator.
I started incorporating these items into my build rather than the standard battlefury approach, and the results have been impressive to say the least. My PA win rate without medallion? 50%. With medallion? 75% (15-5 at the time I'm writing this). After trying out a variety of items and builds, I compiled my build suggestions into the program below. Answer the following questions and it will suggest you an item build to pursue based on the role you want to play, your lane, and other conditions of the game. Hover over each item for descriptions of why you should use it in that situation.
Midlane/Offlane Position 2/3
Use your dagger to farm. Stay away from the wave unless you know its absolutely safe. By only using dagger, you should be able to get 3 out of the 4 creeps in the wave. As an offlane or mid, that's plenty. Use your mana pot once you hit ~75 mana or so. The extra boost in mana should be enough until you get another item to help you sustain your dagger spam (medallion/RoB). If you're mid, gank once you're 6 or if you have an opportunistic rune. If you're offlane, keep a tp scroll ready and watch the other lanes. Dagger can be lethal to someone diving a tower. Once you have medallion, leave your lane for good and start the gank train.
Dagger can let you farm in even the most dangerous of lanes
Work towards your early game items as suggested in the build. Your objective as a 2 or a 3 is to create chaos so your position 1 can farm. Rotate often - with blur they wont see your rotations on the minimap. If you're ganking everywhere, they'll devote more resources to trying to find you and less resources to trying to shut down your carry. Keep them worried, eat their supports. Get in, crit, then get out and run to another lane. With PA it's all about cardio.
If you're building deso, as soon as you have that and vlads go rosh. Dont worry about smoking in, just walk right into the rosh pit. Remember you wont show up on the minimap with blur. As long as your blur status doesnt disappear when you walk in, you didnt show up on the minimap. With deso/medallion/vlads, you can take rosh in about 30-40 seconds. Use your dagger to break his spell shield then blink onto him once it's broken. Keep spamming medallion and blink strike.
Safelane Position 1
If a positon 2 PA's job is to create chaos, a position 1 PA's job is to survive the chaos. Don't take too many risks, blink into battle to clean up. Be careful wasting your bkb charges - remember you're building for end game here, only blow your bkb if you know it's going to be worth it. You can consider going battlefury in the 1 position, but I like going maelstrom if I need something to help farm early. Late game if you're going satanic/skadi, combined with blur you're going to be tanky as all hell. If you toss mjollnir's static charge on yourself, it's going to be very difficult to bring you down.
Blur
Blur is PA's passive. Most people only use the evasion portion of the ability. The good players take advantage of the fact that it also acts as a radar - alerting you any time an enemy (even invisible ones) are within 1600 units of you. Keep a sharp eye on that icon. If it disappears, you might be getting smoke ganked or there might be an invisible unit nearby. This ability is particularly good against stealth units. When you see it go down, toss out some dust and attack them before they jump on you.
Detecting Invisible Units With Blur
Scouting rosh with blur is also quite easy regardless of which side you're on. Standing in these positions will reveal wheither or not anyone is currently in the rosh pit without putting you in harms way. The green circle represents blur's distance (1600 units).
Scouting Roshan From Radiant
Scouting Roshan From Dire
Also take advantage of the fact that if the icon is being displayed, you aren't being displayed on the minimap. Sneak into places you aren't expected to be to find ganks, push lanes without the enemy realizing you're pushing them. I've gotten plenty of rax because the enemy didnt realize I was pushing their lane down. Supports will often tp to a lane without looking, expecting only to find creeps. Make them pay for their mistake.
Priming the prng
PA is notable for one thing - her crits. They're the most powerful in the game, the largest possible source of single instance damage. The feeling of one-shotting an enemy hero is something that few other abilities can match. However, at a tiny 15%, the chance to proc is pretty low and the odds are stacked against you. Like any good poker player though, we can always improve the odds. Enter PRNG.
PRNG stands for Pseudo-Random Number Generation. Essentially it's a method of random number generation that more evenly distributes the chances of success. In the context of dota, it means that there's a far smaller chance of being "streaky" (having a ton of crits in a row, or none at all for a long period of time). If you have the time, take a look at the gamepedia wiki entry on PRNG. The basics though work like this: PA's actual chance to crit on her first attack is 3.222% (not 15%). However, each subsequent attack she does after that increases her chance to crit by another 3.222%. So her 2nd attack will have a 6.444% chance to crit, her 3rd attack will have a 9.666% chance to crit, and so on until the crit procs. Once the crit procs, the percent is reset back to 3.222%. This averages out to her critting 15% of the time over many hits, but each individual attack will have a far different chance to crit on its own.
The quick ones of you will notice that this system can be gamed. If you count your attacks since your last crit, you can compute the probability of a crit on your next attack. The returns aren't that great though - a 3% increase each attack isnt much. Luckily for us, PA doesn't just attack an enemy once then run away. Blink strike gives you an attack speed buff for the next four attacks, so the actual question we should be asking isn't
Instead, it should be:
A single 3% increase across four attacks compounds the chance. Four 3% increases compounds the pain even more. Here're the raw numbers showing what the percent to crit is after a certain amount of attacks without critting.
The takeaway here? You can, and should, be priming your crit before you jump on a hero. If you hit a creep just four times (without critting) before you blink strike a hero, your chance of landing a crit jumps to over 50%. Priming the prng with seven attacks gives you an almost 75% chance to crit. Here's a video of this concept in action - we'll count the number of times we get a crit in the next four attacks after hitting sven seven times first.
The Probability of Critting After 7 Primed Attacks
Fourteen out of the sixteen, or 88%. A bit more than the predicted 75%, but still we can see the power in priming your prng. If you're unsure whether or not you should jump in on a gank, consider the number of attacks you've primed. If there's a bunch in the queue, you have a higher chance of getting a crit off in the gank and making it out with a kill.
Skill Build
I generally go one of two very similar skill builds. If there's a lot of physical harrass in lane I'll go blur at level two:
If I need the extra mobility to evade stuns or as an escape, I'll get blink strike at two instead.
If you want to do a very early rosh, you can max out blur first instead. With maxed out blur you should be able to take rosh with only a medallion, but it cuts down on a lot of your early game ganking capabilities, so it's pretty situational.