Twitch is a stealth assassin that if played correctly can easily make a win out of a loss. This primarily involves convincing your team not to surrender yet even though you are losing. If you are going to play as Twitch there are a few things you must be good at. These involve but are not limited to:
•Spotting wards and oracles
•Last hits
•That annoying Kill Steal
•Being very mobile
•Knowing your limitations
•Back dooring like a pro
This is a build I have been perfecting ever since I first purchased him some years ago. My Twitch build is only for use in a Classic 5v5 battle on Summoners Rift. In 3v3 the map is too small for you to reap the full benefits and in Dominion you die too much to be effective.
*WARNING* This guide is for those players that have experience as Twitch and are looking for improvement. Players without experience may want to search for a more in depth guide.

Pros:
•Stealth allows you to sneak up on enemy and can be used to escape too
•Your poison stacks can help you to kill an enemy if they escape or if you die
•Poison stacks are also good for kill stealing
•No one can back door like you can
•If your build is coming along nicely, farming minions comes really easy
Cons:
•You are the squishiest player in the entire game
•Wards are the death of you
•Xin is the death of you
•Cait is the death of you
•Rammus with a thornmail is the death of you
•Just about any 2v1 sprung on you is the death of you
So really just be prepared to die alot and still cause your team to win.

I have selected these runes to allow a bonus 12.6% attack speed early game which will help you send off those poison arrows as well some armor penetration and attack damage.
With these masteries you will also have bonus attack stats and an all important reduced time dead.

I have listed each item to buy as you should buy it. Obviously Zeal has two items that combine into it but you should try not to b for every item. These are just as you can buy, buy in this order. But because of the cost of the build you defiantly must start with avarice blade to reap the maximum benefits of having the extra gold per 5 seconds. I have used this build ever since I created it. The only interchangeable items are what you turn BF sword into but you must have at least one infinities edge.

The most important thing about Twitch is his ability to go into stealth mode. That is the reason it is maxed out first. Depending on how the game is going you may be able to save the last 1 or 2 stealth levels for when you become a higher level, that is your choice. Personally I enjoy being able to stay stealthed and follow enemies through the jungle for my team to see and it allows for a successful gank, something hard to do when your stealth runs out. Your Debilitating Poison and Expunge are to be leveled depending on the game. If you find your enemies are getting away before a lot of damage is being done then Debilitating Poison is your friend. However, if your enemies seem to be getting away with just the slightest bit of health [under 75 during laning phase (level 1-9), under 125 during ganking phase (level 6-14), under 200 final phase (level 11-18) (final phase you should be level 16-18 any ways but still)] then Expunge will finish them off nicely. Your ultimate, Spray and Pay, comes in handy whenever you are faced with any enemy, or just want to farm minions super quickly (kind of a waste unless you just refuse to help in team fights).

Being the squishy character that you are, I find Revive to be extremely helpful in keeping you out in the field where you belong instead of watching your team. You can use it several times throughout the game and it can really help your team out if the battle seems to be a stalemate. I also enjoy the use of teleport as it gives you a great way to back door and gank effectively as well as to go defend a turret. I used to use fortify as a way to defend turrets against a strong push but as the spell has been removed it is no longer an issue. 1 spell to try might be promote to allow your backdoor to be more successful, although I feel it won’t be as useful in the long run.

It is every stealth players worst nightmare but there is a way to turn it into your best friend. If you have ever played Shacco, Akali, Teemo, Eve, and a few other characters with stealth capabilities then you know how annoying it is to be killed while in stealth mode. It is simply not fair. It is your most useful skill and it has become utterly useless. So how do you determine if you have entered a night mare or found your best friend? Determine how much they are willing to buy it. After all these wards and oracles can become quite pricey and if they are killing you with them then it is worth it. So what is the solution? Don’t allow these tools to affect you. Sometimes this means buying your own oracle to find wards or sometimes it calls for a targeting of a specific player who has that ugly little purple eye floating above their head. Occasionally drastic measures need to take place and you may need to lane swap. Whatever the solution just make sure they are losing money on buying it.

One of the most beneficial things you can do for your team is to back door. It is a simple concept that many people seem to not understand. You go behind enemy lines and destroy the turret/inhibitor and leave. That is it. Nothing too fancy. Just in and out. If you’re looking at turrets it is best to follow some minions in, unless it is below 200 hp. If it is just an inhibitor then go for it (you may want to let enemy minions pass by first). I remember once I won a game by reviving and running under stealth past the enemy team that was charging our base and taking out their nexus. If I had tried to fight I would have been killed under our two towers. That is why I will let my team fight 4v5 if it means I can back door a turret.

This guide is to show my way of playing as twitch. I had to teach myself how to use him and have decided what works best and what doesn’t. Everyone plays differently and this way has won me many of games. If you use this build/way of playing him, please don’t take credit for yourself. I am not asking for personal recognition, but I don’t want people thinking I copied someone else. Just say you found this build online is all that I ask. Remember that it is crucial to know if you can turn the game around or not. If you are down by a turret or two the answer is an absolute yes. Down 4 or 5 turrets and the outlook doesn’t look too good for you.