Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
Forward: This is the first guide I've ever written on anything not school related. Please comment and give advice for possible alterations.
This is a critical damage based guide to build Tristana. It is the most effective build I've used on her when late game hits. Now this build is very weak in team fights early on, since unlike champs such as Tryndamere or Ashe, Trist doesn't have any natural affinity to crit.
The biggest problem you may have with this build is NEVER PURCHASING HP, REGEN, OR RESISTANCES. This is a real glass cannon build. You need to rely on killing the enemy quickly, and if you can't do it quickly do it smart.
While laning, widdle them down from afar till you can jump on them and (if lvl 6) Buster Shot their face. Those will possibly be your only early kills unless you finish off enemies from another fight. If you are in the ganking phases try to stay in mid and farm the creeps and maybe take the tower. I like to stay in lane for 25 mins as long as my teammates don't drop on the defense of the other lanes. It also helps to have wards in river and such.
The beauty of this build is how I've seen it turn my team back from the brink by shear damage dealing. The grid often shows me dealing more damage than Heimer (not a simple task, damn turrets). It is kinda like Sword of the Occult, and Mejai's. It snowballs. May have meager damage to start and be a little frail but if you get it rolling it overwhelms the opposition.
Another note: Order of skills and items may change based on who you are against.
Start with Vampiric Scepter gives you the chance to stay in lane longer the pots or ant dorans item. Plus it converts later into Executioner's Calling.
Next get 2 Avarice Blade. Yes TWO. The total 24% crit plus the 1/sec with both will really make a difference late game. Make sure to get them before 10 mins for max effect. It takes the second one 6 minutes and a few seconds to profit gold directly. The first tho will later be turned into Youmuu's Ghostblade.
Now rush Berserker's Greaves. No ifs/ands/buts about it unless you REALLY need merc treads. The AS buff from greaves means more crits out of your cannon/min. Then Executioner's Calling.
Now rush Infinity Edge in whatever order you can afford. I like to start with B.F.Sword but money doesn't always go that way. If I can't get the sword first I get Cloak of Agility (I am based on scoring crits). Now that IE is finished your crits do over 300% damage to enemies.
Now I make 2 Zeal by selling one Avarice Blade for AS, crit chance, and move speed. Following this is making the first blade into Youmuu's Ghostblade.
By now the game is sometimes long over but not always. Sell that Executioner's Calling for a The Bloodthirster now and then if you can EVER afford it finish the 2 Zeal into 2 Phantom Dancer or sell one to make a Last Whisper for more Armor Pen.
P.S. This is not my build i've taken the build from another site but in my opinion is the best build for Tristana just take care and stay in lane to make the gold than it is a piece of cake :D.Hope you like it.