Twitch

Twitch is an ambush carry. Ambush turns him invisible, letting him walk around a position, cut through the jungle and arrive on the flank of a fight already in progress. No other marksman on this roster chooses their entry angle the way he does.

Poison is the champion's other half. Every auto attack poisons the target, and Contaminate detonates all those stacks at once. That means a Twitch who has been chipping away for twenty seconds can finish several targets from range, even after disengaging. He is extremely fragile and forgives no positioning error.

His ultimate's reach is what really sets him apart. Spray and Pray pierces everything in its line, making him one of the few carries who can hit five enemies at once. Combined with a flank obtained through invisibility, it's the highest damage output a team can field in a grouped fight.

Everything else is fragile. His base range is ordinary, he has no escape button once Ambush is spent, and his health pool is among the lowest in the game. His early lane is weak: his harassment asks him to step closer, which is exactly what a fragile carry doesn't want. And his invisibility falls apart against properly placed vision.

Don't use Ambush to harass. It's your only survival and repositioning tool: spent to win two auto attacks, it leaves you with no answer to the enemy's next engage. Hold it, and play the lane like an ordinary carry, behind your wave.

Venom Cask controls space as much as it poisons: it slows an area, which helps your support engage or lets you both disengage. Build poison stacks naturally through your attacks, and save Contaminate to finish a target walking away thinking they're safe. A level one ambush from the river brush is a real option, but it works exactly once, after that they ward.

The sharpest spike is your ultimate. Before it you're a below-average carry. After it you're the biggest teamfight threat in the game, provided you're positioned well when you press it.

After that, attack speed matters more than raw damage, because your poison stacks on hit count. An attack speed item therefore raises both your attacks and the size of your Contaminate detonation. Armor penetration belongs late, once the enemy team starts stacking resistances specifically for you.

Your fight starts before the fight. Use invisibility to sit on a flank, along the line the enemy will group on, and wait. That placement is most of your job: a well-positioned Twitch only has to press the button.

When you fire Spray and Pray you're stationary and exposed, so never start it before the enemy's crowd control has been spent. If the fight begins without you, that's fine: arrive on the second wave, once positions have loosened and health bars are already down. That's when your ultimate returns the most.