Trundle Build Guide by GargoPat
Not Updated For Current Season
This guide has not yet been updated for the current season. Please keep this in mind while reading. You can see the most recently updated guides on the browse guides page.
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.
Introduction ~ About the Author
I'm Gargopat, a league of legends player with a real knack for jungling (as you can tell by my profile, which contains all jungling guides). This is my first guide on MobaFire, and I wanted it to be on one of my Favorite champions, Trundle- The troll king. When I started playing him, he was the Cursed troll, which was cooler in my opinion, but thanks to riot, that got shattered. I'll be sharing my Masteries, Runes, Items, and Skills to help even a new Trundle player succeed in his Trolling. This might not be the top rated guide on MobaFire, but You will not regret reading it! And please remember that you can change the build to your liking, there is nothing from stopping you from taking this and customizing it into your own. Please rate and leave your comments for me!
What is Trundle all about?
Trundle is a very good jungler, adept at ganking and counter-jungling. He is a strong duelist who saps the enemy's attack damage and boosts his own, and is adept at sticking to a target and ripping them apart. His early game is one of the best, as he has some of the highest base stats in the game. His late game is different though, as those early good stats are balanced by finishing as some of the lowest. (One of the lowest base armor of any champion with 68 at level 18). With the right items, masteries and runes, Trundle can be a very tanky DPS champion good at killing off foes by sapping their stats with his abilities, and is able to keep himself decently sustained in the jungle. He is also a decent pick for top lane, being one of the few counters to Yorick, the king of the top lane.
Trundle is a great duelist, able to sap the attack damage of an enemy, and if they try to run, keep them close with his abilities, which I will explain later.
|+ Strong Early Game
+ Great Duelist
+ Terrific Sustain
+ Good Jungler / Counter-Jungler
|Trundle is a tanky, melee DPS Champion that can benefit from a variety of builds. You can build him to have insane attack damage through items such as Last Whisper or The Bloodthirster, or have him be a tank with items like Warmog's Armor or Randuin's Omen. His passive gives him great sustain in the jungle or solo lane, and his kit helps him stick to a target and kill it. His signature ability, Pillar of Ice, offers great utility in his ganks and teamfights.|
|- Sub-Par late game
- Easily Kited and harassed
- No Hard Crowd control
- No AOE damage
|Trundle has less-then-impressive late game, as his late game stats are rather disappointing. He is in the bottom 5 champions for lowest armor values at level 18. He has decent health scaling, that can be increased by runes or masteries, but the rest of his level 18 stats are lackluster. Trundle is extremely susceptible to kiting and harass, as he has no gap-closers. If he can't get in melee range of an enemy, or in range of Blade of the Ruined King's active, then he won't be able to catch his target, especially if they evade his Pillar of Ice.|
Greater Mark of Attack Damage
Greater Seal of Armor
Greater Glyph of Scaling Magic Resist
Greater Quintessence of Movement Speed
Greater Mark of Attack Damage: Some damage to start you off. Clears the camps faster and gives you a jump start if your AD. They help clearing the jungle faster then arpen marks, as jungle creeps have very little armor in the first place. However, they don't scale into late game as well as armor pen marks.
Greater Seal of Armor: Armor will prevent the camps from hitting to hard, and lets you survive poke in top lane. These are just the best available seals for almost any champion at the moment. If you are feeling brave, you can swap these out for Greater Seal of Scaling Health, for some late-game tankiness.
Greater Glyph of Scaling Magic Resist: At level 9, these runes will have given you more MR then the flat counterparts. Simply the best you can go with, as they give 2x the amount of MR from the flat glyphs at max level. You won't be needing any level 1 magic resist, so scaling MR will be most beneficial to almost any jungler.
Greater Quintessence of Movement Speed: Lets you run around the jungle and in between lanes faster. If you take Trinity Force, then you don't have to take these, as Trinity Force provides Trundle with all the movement speed he really needs, but you can still take both to get as much chasing power as possible!
OTHER RUNE OPTIONS
Greater Mark of Lethality
Greater Seal of Armor
Greater Glyph of Magic Resist
Greater Quintessence of Attack Damage
greater mark of Armor penetration: Mainly for the top lane, it helps somewhat against the jungle camps, but not as much as the flat AD marks. These runes can negate the Cloth Armor & Health Potions x5 start. It doesn't offer as much damage in the early levels asflat AD marks, but come level 6-7, they will start to outperform flat AD marks.
Greater Glyph of Magic Resist: Flat MR glyphs will provide more defense against and ap-based poke champ, such as Nidalee or Teemo. These runes are only viable in a solo lane however, as Jungle Trundle doesn't need any early-game Magic Resist. If you are against an ad top with no magic damage, then scaling MR glyphs will serve you better.
Greater Quintessence of Attack Damage/ greater quintessence of armor penetration: Either of these will do, but I wouldn't double armor pen marks with armor pen quints. Flat AD quints are acceptable in any role Trundle plays.
Greater Quintessence of Life Steal: If your new, and are just learning to jungle, you can use these quints for the extra survivability in the jungle, as the life steal will keep you sustained. The life steal will be improved with frozen kingdom, as explained in the abilities chapter.
: This mastery improves Ghost, Ignite, and Exhaust, 3 spells that Trundle can make very good use of. You should always put a point into this, no matter what!!
: A little bonus attack speed helps your jungling until you buy some attack speed items.
: Extra damage on jungle monsters and minions! Lets you farm more effectively.
: Some scaling AD, mainly to help us get to the third row in the offense tree.
- Weapon Expertise : Extra armor penetration is always a good choice, and gets more use than another point in Fury .
: This grants 10 bonus gold every time you use Smite. Very useful early game, but not so much late game. Still worth the point though! Don't put a point into it unless you are jungling, as it doesn't improve any of the spells you take when laning.
- Perseverance: Taking this will grant extra health regeneration in between jungle camps. This amount can be increased with Spirit Visage and while standing on frozen kingdom.
: Some scaling health into late game helps Trundle out a lot.
: Show those monsters whose boss.
: Extra armor to reduce damage taken from monsters and champions.
: A mini Thornmail that only works on monsters.
reduces the duration of slows, stuns, etc.,
reduces the effectiveness of slows themselves, not the duration. Taking one or both of these masteries will improve your escapability by a huge amount, especially when combined with tenacity from an item.
: A free Greater Quintessence of Health. You will really notice when you don't take this, as your jungling will be tougher thanks to less health. ALWAYS take a point in this mastery!
: Extra tenacity on Trundle makes slows, snares and other forms of crowd control a joke. Stacking with tenacity items will grant a total of 45% tenacity.
: Increasing armor and magic resist bonuses from items and runes. This stacks well with
, as well as
. The 5% is so small though, it might not be worth putting points into this mastery instead of putting them into something else, like
, making this a situational mastery.
- Honor Guard : Reduced damage? Whats not to love? It stacks with Tough Skin , Unyielding and Block , and if you picked up an early Doran's Shield, you will be negating a TON of damage.
: Reducing the cooldown on Flash is extremely useful, but if you aren't taking Flash, then take this point and put it into
: One point just to get us into the second row of masteries. Two points if you're not taking Flash.
: Extra mana regeneration helps us when we don't have the blue buff.
: Greater cooldown on Smite, and any other spell. Very useful, as Trundle relies heavily on summoner spells.
: Extra duration on neutral buffs from golems and lizards, very helpful early game, and if you manage to kill an enemy with any transferable buff.
Take 9-21-0 masteries when jungling. The important ones are Tenacious and Relentless . These 2 masteries will make Trundle near-immune to all forms of CC when combined with an item that gives tenacity. Legendary Armor will improve the effectiveness of any armor or tanky items you buy. When going top lane, I pick 21-9-0 masteries, picking up all of the armor pen masteries and Havoc mastery, to increase my overall damage output. When playing as a tank, usually take the 0-21-9 mastery setup.
Smite: Trundle needs this to jungle! It makes your clear speed that much faster, and helps with stealing the enemy teams buffs and dragon. It also increases your counter jungle speed significantly, and the extra gold from Summoner's Resolve will add up, giving a free ward after 8 uses, and a health potion after 4.
Ghost: Moving faster to stick to a foe or escape a sticky situation. The movement bonus is increased with Summoner's Wrath . The only downside when comparing this spell to Flash, is that Ghost doesn't have the element of surprise. Its really good for running through an enemy team (thanks to the unit collision ignored), and you can run straight at your target and take them down. And if you have Sunfire Cape, you will damage all enemies you run through for a bit of extra damage.
Flash: Flashing over a wall if usually safer then ghosting away from a teamfight that's gone sour. Its the spell of 1001 uses, and a good pick for any champion. You can use it to close the gap for that last hit needed to kill, or use it to escape over a wall away from death.
Ignite: Take it in the top lane for the last bit of damage to kills a fleeing foe. Combining it with Subjugate will stack up the damage while you pummel them with basic attacks and Chomp. It is also a great spell to take against sustained champions like Dr. Mundo and Sion.
Exhaust: Slowing a foe or carry when ganking or in a teamfight. It's sort of like having 2 of your ultimate, only one doesn't last as long. With Summoner's Wrath , the target also loses 10 armor and magic resist, making them easier to kill. If you feel you fail at ganks, this will help immensely. Try to save it until after the target uses Flash, so that you can secure the kill.
Teleport: Mainly used in the top lane, only take it if your team has a TON of CC or gap closers: This way you won't need to take ghost or flash. It helps to push another turret, or quickly save one from destruction. You should take Summoner's Insight with this spell, and the distortion enhancement, to make the cooldown and cast time as short as possible.
I usually take Flash for general usefulness; ganking, escaping, ensuring that last kill, etc. Lately though I found Ghost to be a more useful skill, as it helps Trundle fill out his main role: sticking to an enemy and taking it apart. I place either one of these on my D key, because that's the key I am most likely to smash in a mad rush to escape a tough scenario, or chase a fleeing foe. Smite goes on F, and although Trundle is one of the few junglers who can jungle without it, I always take it just to be on the safe side. You can however, take Exhaust or Ghost in place of flash to assist in ganking and Champion killing. You can also take Teleport if you need to get from place to place quickly.
Take Ignite for most of the time when top laning, and/or Teleport. Exhaust in the top lane combined with Subjugate will make you near-unkillable, even against the popular bully Darius. Remember that when going tank, your job is to be a tanky as possible and to weaken enemies, not kill them yourself. That's why I choose Ghost and Exhaust as they help my team secure kills, as opposed to securing myself kills.
King's Tribute: This passive heals Trundle for a small % of any unit's maximum health upon dying when they are near Trundle. That means if an incredibly tanky champ like Garen dies, Trundle is going to heal for a large amount of health. This is a great passive for a jungler, each time he kills a monster, he heals for a percent of that monsters max health. The bigger the monster, the more Trundle will heal. It also works on minions, whether you are the jungler just passing through the lane, or laning and farming.
Chomp: Trundle's next basic attack will bite the opponent, dealing bonus damage, slowing them by 75% for a brief moment, increasing his own attack damage, and draining the opponents attack damage. Note that this resets Trundle's auto-attack timer, meaning you can use it right after a basic attack to maximize your DPS. The buff duration is longer then the cooldown, and with a 4 second base cooldown, you can constantly be buffing yourself up. The AD buff does not stack, but will reset its timer when it is cast before the buff expires. Always max this ability first, as it is Trundle's only damaging tool in his kit. It makes Trundle an excellent duelist, and great at clearing the jungle quickly, despite having no AOE damage in his kit.
- This ability applies on-hit effects like the Elder Lizard Debuff and The Black Cleaver's armor reduction.
- This ability will be blocked by blinds like Blinding Dart, and spell shields like Spell Shield.
frozen kingdom Frozen Kingdom: Coats a large area with ice for 8 seconds. While Trundle stands on this, he gains inceased attack speed, increased movement speed, and increased healing from all sources. This includes the healing from King's Tribute. Always remember to cast it in a teamfight, and you can use the movement speed bonus to chase or escape from a foe. If an enemy tries to kite you off the area, you can use Pillar of Ice to hinder their progress and keep them on it for as long as possible, as Trundle fights best when on it. Be careful when placing it, if using it to jungle, you can accidentally reveal your location to the enemy team, for they will see the ice on the ground through nearby walls.
- The healing effect while standing on this ability increases healing from Health Potions, and stacks with Spirit Visage's healing passive. It also increases base health regeneration.
Pillar of ice: This is Trundle's signature ability. Trundle creates a beacon of unpassable terrain that slows enemies near it. Trundle's signature ability. This ability is the most useful tool in Trundle's arsenal, and proper use will separate decent players from great players. You can use it to split up the enemy team, disengage a teamfight, ganka lane, save an ally, catch an enemy off guard, etc. It deals 1 true damage, purely to draw turret aggro, so be wary when using it near a turret. This ability also interrupts channeling abilities like Fiddlesticks Drain, when used directly underneath the channeling champion, and since it displaces a champion standing on top of it, it can reveal Teemo's stealth.
- If you watch the Trundle Champion spotlight (link is in the guide), around the 2:00 mark, you can see a proper use of Pillar of Ice.
- Casting it underneath a channeling champion will interupt their channel, such as Death Lotus or Drain.
- It can block the travel of certain abilities, such as Tristana's Rocket Jump, stopping them in mid-air.
Subjugate: Trundle immediately steals a large percentage of the targets armor and magic resist, as well as a large percentage of their maximum health as magic damage. (Half initially, half over 4 seconds). The armor and magic resist is returned over 4 seconds. This ability makes Trundle beefier, and melts tanky, high-health targets. It is best used on an enemy tank so soften them up, or on whoever your team is focusing, say the target that engaged a team fight. The heal amount can be increased with Spirit Visage, but not the magic damage. You should never engage with this spell, but save it for when you have lost some health, so that you can steal it from them while still fighting.
- Be sure to target the tankiest member of their team!
- The AP scaling is very poor, so you won't get any use out of building AP on Trundle.
Skill Sequence (Jungle)Chomp at level one, it's essential for Jungling, and max it first. It makes champion killing easier, and increases the amount of AD the victim will lose. Take a point in Frozen Kingdom at level 2, but max it third. Max Pillar of Ice second, with your initial point at level 3. Maxing it second will improve the effectiveness of your ganks. It's great for ganking and team fights, splitting up enemies and slowing them. Take points in Subjugate whenever possible. (6, 11, and 16). Subjugate Is especially important, as it makes even the beefiest enemies melt while being affected.
Skill Sequence (Solo top)frozen kingdom second instead of Pillar of Ice. This makes a skirmish in lane easier as you will hit harder, move faster and it will give you more sustain in lane. The points in Chomp and Subjugate stay the same.
Mercury's Treads: Extra tenacity? Yes please! Usually my boots of choice, but if they have little to no AP-based champs, then you can take Ninja Tabi, and substitute another tenacity item into your build.
- Grants Magic Resist
- Grants Tenacity
- Makes you run faster
Spirit of the Ancient Golem: Tankyness and tenacity. A good pick for Trundle, but if you have Mercury's Treads you might as well not purchase this item. Helps clear the jungle camps faster when your looking for extra farm throughout the game.
- Grants tons of health
- Grants Cooldown Reduction
- Grants Tenacity
Wriggle's Lantern: I take this over any item built from Spirit Stone ONLY because of the unique passive. 100 bonus magic damage on every basic attack ( that includes Chomp). This makes clearing the jungle easier and faster, meaning you might not need to smite off the golems or lizards. Late game though, I always trade it up for something more useful, after I have finished the rest of my build.
- Bonus magic damage for clearing camps quickly
- Life steal for sustain
- Free re-usable ward
Frozen Mallet: A must-have for Trundle. Allows him to take more hits, and stick to a foe while taking it apart. Slows foes from escaping the clutches of your team. I always, always, ALWAYS take this item no matter what. Its like how ADCs always get The Bloodthirster.
- Tons of health
- More CC on every attack
Sunfire Cape: A great passive makes for a tanky offensive item. If you need to go super tanky though, I'd recommend buying something suck as a Warmog's Armor instead, as this item gives less than 50% of the health from a Warmog's Armor, or Randuin's Omen, as it gives more health and armor.
- More armor and health
- Consistent magic damage every second
The Black Cleaver: A great AD item, thanks to Chomp and basic attacks, your target will be losing both Attack damage and armor. Topped with Subjugate, your target will be losing Health, Attack Damage, Armor, and Magic Resist. Also gives a little health for durability. When comparing it to the Last Whisper, the black cleaver takes longer to reduce armor (each basic attack reduced armor, meaning the first hit will not deal bonus damage from the armor reduction, it applies to the following hits). It also means that your entire team can hit harder, so it's more about whether you want to soften them for your team, or whether you want to burst them down yourself.
- Health and Damage
- Armor penetration
- Cooldown reduction
Blade of the Ruined King: All of your basic attacks gain 5% Health shred. This means the more health they have, the more damage you do. A great DPS item, the lifesteal and attack speed will tie in nicely with The Black Cleaver and Chomp. The unique active also helps slow fleeing foes, allowing you to close the gap with Ghost, Flash, or frozen kingdom and apply basic attacks to trigger the passive from Frozen Mallet.
- Life steal gives more sustain
- Health % shred on every attack
- Active effect slows and steals 15% of max HP and heals for same amount
Randuin's Omen: Armor and health, combined with the unique passive of slowing the attack speed of foes you hit you. The unique active ties in with Blade of the Ruined King, Frozen Mallet, Flash, Ghost, and The Black Cleaver as seen above. This item is a very solid choice against enemy champions with tons of attack speed, such as Udyr, Jax and Xin Zhao.
- Slows anyone who attacks you
- Active slows in an AOE
- Tons of health and armor
Spirit Visage: If you really want, you can take this item. Combining it with the heal from your passive, the healing effect from frozen kingdom, and top it off with lifesteal from Wriggle's Lantern or Blade of the Ruined King, you will have a huge amount of sustain in the jungle and teamfights. It also grants a huge amount of magic resist, but if the enemy team has little to no AP, consider a substitute.
- Tons of magic resist
- Increased Healing from all sources for great sustain
- Very cheap (for now, edits coming in upcoming patch)
Sheen: This item should be purchased relatively early in the game for Trundle. It enhances your next basic attack (including Chomp) to deal bonus damage equal to 100% of your current AD. This amps up the power of Chomp by a huge amount!
Iceborn Gauntlet: Ups that damage to 125%, and makes it deal that same amount hit enemies near the target. It also grants 70 armor! That's the same amount you get from Randuin's Omen! It also ensures that Trundle never runs out of mana. The AOE slow also helps catch fleeing foes. Works best on a tankier build.
- Tons of armor
- Unique passive adds AOE slow and damage to basic attacks
- Cooldown reduction
- Solves all mana problems
Trinity Force: Tons of damage! A really good, all-around item for almost any top laner or jungler. Trundle benefits nicely with all of the stats it offers, including the unique passives. This item works well on any build you choose, as all of its stats work well on Trundle.
- Grants stats that benefits Trundle's every need
- Tons of damage
When jungling, I would usually buy the Wriggle's Lantern for the early armor and lifesteal, and being able to ward top lane after a gank. I always buy the Mercury's Treads for extra tenacity, as Trundle's kit ties in with it very nicely. When going top lane, I tend to build as a healthy bruiser, adept at dishing out and taking damage. When playing as a tank in any role, I will build one or two support-based items, IE) Runic Bulwark and Locket of the Iron Solari to make me tankier. No matter what role though, I ALWAYS get a Frozen Mallet as it makes my job of sticking to a target easier. It also gives me more health and a little bit of AD. Whenever I'm not being the tank, I usually get a Blade of the Ruined King to slow and keep my enemies weak while I take them apart. Randuin's Omen and Sunfire Cape are healthy choices for any build you chose.
Creeping / Jungling
Follow this jungle order and success will follow:
Ancient Golem -> Wolves-> Wraiths -> Elder Lizard -> Golems -> Gank (At Level 3)
Ancient Golem (smiteless)-> Elder Lizard ( Smite)-> Gank ( you will be level 3)
When getting the blue golem, it is usually best to get a smitless leash, and then run straight to the red lizard camp, and smite that bad boy off. It will out you straight up to level 3, around the 3:00 mark. If you can't get a smiteless, then just smite it and go to the wolf camp.
Afterwards, pick up small golems, followed by wolves and wraiths as they respawn, and then give the mid player the Blue Buff once it respawns around the 7:00 mark( If they don't need it, take it for yourself). Be sure to take the Red Buff as often as possible to ensure it does not get stolen from you. Also be sure to get the dragon at earliest convenience, such as when bot can come assist you, like right after a gank on bot lane that resulted in a double kill for your team, or forced the enemy to both recall to their base. This will allows an uncontested dragon, even if they have wards. (You should be at least level 10). And if you can keep track of the enemy junglers movementsby warding key areas of their jungle, you can easily sneak into their jungle and steals camps and buffs. Using the Wriggle's Lantern's free ward at the enemy blue around the 6:00 minute mark will show you when to get to the enemy blue buff and steal it with Smite, or around the 7:00 minute mark for red buff. If the enemy jungler starts at red buff, then make it 6:00 for red buff, and 7:00 for blue buff.
Note that the camps are at a 5:00 respawn, so killing the camps at about 2:05-2:10 means they will respawn around 7:00. Make sure to place a ward there beforehand for stealing, but not to early, as wards only last 3:00 minutes.
Sometimes, all you have to do is poke your head out of a nearby bush, and they will sh*t themselves and Flash away. When this happens, come back to that lane shortly for a gank. If they don't have Flash ready and available, then they will not be able to escape your slows and Pillar of Ice. If they have no escapes or Flash, they are an extremely easy kill.
One thing too many people do is suddenly play aggressively when their jungler comes to their lane. They don't play passively enough, and end up giving away their teammates position. Make sure they let the enemy push their lane, as it is easier to gank a pushed lane. Also make sure they don't give away your position. Otherwise, you're gonna have a bad time ganking.
Trundle is most effective with his team. Certain teammates paired with trundle can make him shine in a teamfight. Some of his good teammates are:
- Anivia: Her Crystallize is like a wider version of Pillar of Ice. Pillar of Ice can also be cast to keep enemies on her Glacial Storm's AOE for a longer duration.
- Ashe: Passive slows on her basic attacks from Frost Shot means you can keep up with an enemy and get the kill.
- Elise: If she leads with her Cocoon, it will set you up for an easy gank with Pillar of Ice.
- Fiddlesticks: Like Anivia's ult, Pillar of Ice can be used to keep enemies on Crowstorm for the full duration.
- Gangplank: Fighting an enemy on top of frozen kingdom, and underneath Cannon Barrage will turn a battle in your favor, allowing you to kill, or escape a tough situation.
- Janna: Be sure to cast frozen kingdom underneath her Monsoon will get the most benefit from the heal. Her passive, Tailwind grants Trundle bonus movement speed, meaning you may not have to take movement speed Quints if you don't want to.
- Jarvan IV: His Cataclysm will prevent enemies from escaping, giving you enough time to kill them, or slow them if they try to escape.
- Kog'Maw: Pillar of Ice can prevent them from escaping his Icathian Surprise.
- Nocturne: While he is casting Unspeakable Horror, you can use Pillar of Ice to prevent them from getting out of range in time.
- Ezreal, Lux, Draven: These three with a long-range skillshot ultimate can have an easier time landing them if you set them up with Pillar of Ice.
- Miss Fortune: Catching enemies with Pillar of Ice underneath her Bullet Time will WRECK the enemy team.
- Nunu: Slowing a foe with Chomp and Pillar of Ice can give Nunu enough time to get in range for Ice Blast or Absolute Zero.
- Soraka: Her Wish heal amount is increased while standing on frozen kingdom. While it may be hard to predict when she will cast it, good timing will allow you to heal a large chunk of health.
- Taric: Pillar of Ice keeps them in range of Dazzle, and Imbue heals more while standing on frozen kingdom.
- Thresh: He has a ton of toys to keep and enemy close enough to kill or assist in a kill.
- Zyra: Her Grasping Roots make it easier for you to get in and have a successful gank.
Trundle is not a very effective initiator, but he can split up the enemy team with his Pillar of Ice. Thanks to Frozen Mallet, Trundle can stick to an enemy and kill it. When in a team fight, try to place your Frozen kingdom so that you can fight in the exact middle of it, so if you have to chase, (which hopefully you won't!) you'll have plenty of ground to run on.
Remember, it's okay if you die! You're not the AD or AP carry, so if you die softening up the enemy team enough so that your team wins, it's a success.
If the enemy team decides to retreat, then you can apply all your CC to stop them. Casting your Pillar of Ice can hinder their progress, and combine it with the slows from Chomp, Frozen Mallet, Iceborn Gauntlet, Exhaust, and the unique active from Blade of the Ruined King, you can ensure that they will fall to the clutches of your team.
If you need to retreat, you can still use almost all of these tricks to stop them from catching and killing your team mates, mainly the carries. This is called peeling, and also applies to counter-initiating.
Trundle has the potential to heal incredible amounts of health from many sources. This healing can also increase his sustain in the solo lane or the jungle. My build has these sources:
-6% from King's Tribute
-20% increased healing from all sources from Spirit Visage
-20% increased healing from all sources from frozen kingdom
-15% lifesteal from Blade of the Ruined King
-28% of targets maximum health from Subjugate
-Optional Greater Quintessence of Life Steal X 3.
With this sustain, Trundle can stay in the jungle or solo lane much longer then you'd expect, and longer then many other laners or junglers. For example, in the top lane against someone like Darius, you can easily win the sustain game. Darius can poke at you with Decimate, but he has no sustain, so he won't be able to shrug off your trades as well as you can. For each time you nail a last hit on a minion, you will heal some health back. It works better on frozen kingdom, as do health potions. This will force him to play the sustain game as well, and therefore spend more money on health potions and health items.
Trundle is a very fun champion to play, even more now thanks to his upcoming rework. I will continue to update this guide whenever it is needed. Remember that this is just my personal guide, and you can change your own build however you want. If you like it, give me some feedback, and maybe an upvote. And if you hate it, please just ignore it and move onto another guide, there's no need to hate on it, and say that "it sucks!" or whatever. Keep negative opinions to yourself. Thanks for checking my Trundle guide, and if you liked it, make sure to check out my Skarner guide!