Hi, my name is Stebsy. I have been main Trundle Jg since Season 6. I mainly Jg with him, sometimes I support, but very rarely and with low skill. My experience is the Jg. He can be extremely powerful if played correctly.

He is very strong early game dueler and with Skirmishers almost no one can take you. Mid/Late game you need to be smart with your ult. Use it on their tanks and kill their carries or sit back and shred their tanks, its situational.

• Greater Quintessence of Attack Speed: Trundle, Utilizes attack speed extremely well and most of his damage comes from his attack speed and procs on hit. Attack speed is a must, this is the most efficient way to start.
  
• Greater Mark of Attack Damage: The base damage, enough for fast clears, I experimented with Greater Mark of Attack Speed but because you don't buy a large amount of attack damage I felt the early damage and the presence of this small amount of damage into late game strengthened Trundle
  
• Greater Glyph of Magic Resist: You can use these or Greater Glyph of Scaling Magic Resist. I prefer flat because you will be ganking around lvl 4 and scaling won't over take until lvl 9.
  
• Greater Seal of Armor: Same reason as above. I would not use anything else here. He does not benefit from the Greater Seal of Health.

The Mobafire calculator doesn't work for me. There are two different masteries you can go with trundle.
Damage:
18/0/12
Fervor of Battle
Fervor is extremely powerful for trundle because his kit lacks damage and he is an auto attack champ. This allows you to build up a decent amount of damage quickly and combined with Chomp will mean you are outputting a lot of damage.

*I highly recommend this with the standard build as it complements the kit.

Tank:
12/0/18
Grasp of the Undying
Grasp is great for tanking, combined with other defensive masteries in the resolve tree it boosts your survivability, but hurts your damage, obviously.

*I recommend this with the alternative build listed. This is great for tanking when your team lacks one.

Pros + Extremely strong dueler + Can be very effective in team fights Subjugate and Pillar of Ice + Extremely strong ganker Pillar of Ice + Fast Jungle Clear + Attack speed steroid Frozen Domain + Steals stats Subjugate Chomp + Great team fight King's Tribute He has extremely fast jungle clear. You don't need any pots for a full clear, as long as you start blue for mana regen. This puts you ahead of enemy jungler in terms on gold and you can get your jungle item and a dagger on first back. He is an extremely strong ganker. His Pillar of Ice can be used offensively and defensively. He is a hard counter to Katarina and Miss Fortune this is becuase his Pillar of Ice can instantly cancel both of their ultimates. Most of them are not expecting it either with takes away their teams power.

Cons - Squishy at the beginning - Reliant on his ultimate Subjugate - Lacks mobility, no reliable escape besides Pillar of Ice - Hi cooldown on Pillar of Ice - Only single target damage Chomp - Can be kited if not played correctly He has no gap closer, so you effectively need to walk onto the enemy. This makes ganks a little harder, though if you can get onto them or behind them without blowing your pillar you can basically guarantee a kill. His is very squishy, when you have tanking items and is very reliant on his ult when dueling.

Early game is pretty straight forward on trundle. You can do two different strategies.

Safe clear
This is a complete clear. You do not need any pots, as long as you always start BLUE. Just clear the entire jungle minus skuttles and this will put you ahead/on par with enemy jungler. This is by far the best clear for Solo Queue. This gives you lvl 4 and enough gold for skirmishers and dagger. This is a large advantage on the enemy jungler.

Gank clear
This is when you simply take three camps including the buffs then gank mid/top. I do not recommend this but it is doable and I tried it alot. I found this stopped working High silver/low gold and put me behind the enemy jungler.

Invading
I don't like to invade on trundle. Its something I have done alot of, I can say that Trundle is one of the strongest duelists in the game at level 1 and it is possible that it is a decent strategy. Someone should try it consistently and let me know if it works.

Being invaded
If an enemy Jungler is dumb enough to invade you pre lvl 4, before your first back. Its their mistake. Don't run, you won't be low HP so you will most likely completely destroy them, just keep pillar waiting for them when they run or if you need to run. The only champ I dont recommend going 1v1 with that early is Lee Sin though I usually ban him for that reason.

After your initial back, taking skirmishers. Continue to farm and look for opportunities to gank. Do not force ganks it will put you behind. Just look for objectives Dragon/Rift. If you see the enemy jungler try to gank the same side of the map you are on top/bot you should head there immediately for the counter gank. If you are on the opposite side I usually go and counter jungle/ward their jungle.

Note*****
Your pillar is the single best ganking tool you have. If you can get onto an enemy they are dead. Do not use your pillar until they have flashed. They will know what you can do with it and will wait until you have used it to flash. Do not use it until they have flashed and its a guaranteed kill. The only person who can trump you on ganks is Syndra with her knock back.

This is when you have all or close to all your items complete. Your role in team fights can vary depending on what is needed. If your take has great dive, you can sit back and peel your ADC or you can kill their tanks. Its up to you. You are a tank shredder and if they over extend I like to walk forward. Zone their Carries with my pillar and then let my team shred their tanks.

I will add more to this guide as time goes on. Keep me posted if you use the guide. It has worked well for me to Plat, I will continue to use him until I get Diamond hopefully.