Trundle's Q damage and AD buff allow for nice trades early on, however due to it being his only damaging ability he can be out-traded. His other two abilities are more for all-out 1v1ing, pushing, or escaping a gank. Use Q's and basics to harass and trade whenever the enemy engages. Try to bite and use the slow to get a few basics in unless they retreat behind minions, at which point use the time to farm freely. Do not get cocky, it is easy to think you can duel an opponent if you land a few Q's, but many top laners out damage him when neither has many items. As Trundle, your whole objective is to get as OP as possible by mid-game. This is done by simple trades, farming, pushing, and dying to the enemy as little as possible. ALWAYS STAY IN LANE. Your sustain is really good and you will need the farm/experience advantage, plus you may be able to push tower which will help you later. Once you have farmed a little and had some skirmishes, get your tiamat and begin building Trinity Force, even if you can get vampiric scepter, don't, it is more beneficial to rush tiamat and finish the hydra after Trin Force. The tiamat should give you enough damage and wav clear to 1v1 the enemy champion and push his tower easily. Remember; stay in lane, farm, die as little as possible, and rush tiamat.

Since Trundle can be out-damaged and out-tanked in late game, his mid game is extremely important. It is important to keep pressure on your lane. With Hydra and Trin Force, and finished boots; you are fast, a little beefy, and have a lot of damage and wave clear plus great sustain. You should be able to 1v1 anyone and if they have to bring two people top to stop you, your teammates can capitalize on it. If no one comes to stop you, keep going, with an understimating team, you can take two towers and and inhibitor while the enemies fight your team, even if the enemy wins a teamfight, they have to make a bad decision; they either team push and allow you to take an ihibitor and possibly hit nexus towers, or they all go back to stop your push and have to give up objectives whether that is dragon, baron, or towers. No matter what, try to push as may towers in your lane as you can, Q and W make towers just melt, and even if someone starts hitting you, try to finish the tower, you may not get another chance to take it down. Plus a simple pillar between you and the enemy hitting you is sometimes all it takes to get away. It is worth giving your life for a tower because they are worth more in the long run.

When the teams have started grouping up and 3-5 man skirmishes erupt, your role is to be aware and split push. With beefyness from Trin Force and Spirit Visage, and wave clear plus damage from hydra, along with your speed from boots and Trin Force, pushing is a breeze, you can fight any one person and escape any other amount. If the enemy wins a teamfight, push; they have tocome back and stop and give up objectives, or try to counterpush, which should not work because your early game push should have given you a large headstart. once you get an inhibitor, begin pushing other lanes with your team and become part of teamfights. Your role in teamfights is to steal the enemy tank's defensive stats with ult, then run headfirst and assassinate the carries, dishing out as much damage with q's, ults, BoRK and Hydra actives, and as much disruption with hydra passive and pillars, as possible.

Laning:
Stay safe, rush tiamat--finish Hydra AFTER Trinity Force (Even if you CAN get Hydra or Vampiric scepter before Trin Force, DON'T!) Push hard.

Mid-Game:
Keep constant pressure on lane; punish enemies for roaming to other lanes by split pushing, counter-jungle whilst pushing

Team-Fighting:
Split push to create a situation where the enemy team has only bad decisions to make, whether stopping your push and forfeiting objectives, or counter-pushing (which shouldn't work due to your headstart from pushing lane earlier)
AFTER INHIBITOR OR INHIBITOR TURRET
It is finally okay to quit pushing top so hard and join your team for teamfights. Steal enemy tank's defensive stats with ult, dive in and assassinate carries, dishing out as much damage and discruption as possible using BoRK and Hydra Actives and effective pillars.

Marks: +0.95 Attack Damage, +0.93% crit chance (2)
Seals: +1 armor, -0.36% cooldowns
Glyphs: +0.64% attack speed, +1.34% magic resist OR +0.7 armor
Quints: +4.46% crit damage, +2.25 attack damage (2)

0, 30, 0

OR

9, 17, 4
OFFENSE: Fury, Sorcery, Spell Weaving

DEFENSE: Block, Enchanted Armor, Unyielding, Veteran's Scars, Juggernaut, Hardiness, Perseverance, Reinforced Armor, Second Wind

UTILITY: Fleet of Foot, Meditation