Trundle is very powerful at location-based combat. Try to draw him off of his Frozen Domain.
Make sure to get out of his Pillar of Ice as quickly as possible, as it significantly slows you down.
The stat comparisons shown on this page show several valuable Sett vs. Trundle counter stats that may help you appreciate the distinctions between the two. Sett’s KDA ratio ([kills + assists] / deaths) of NaN is more than Trundle’s ratio of NaN, highlighting that Sett may be more central to his team's team fighting potential than Trundle..
Sett often has a similar longest killing spree as his opponent does. On average, he takes less damage than Trundle. This commonly reflects different amounts of tankyness; however, it can also indicate that the one champion has less agility and thus is not able to escape additional harm when engaged or poked.
Both League of Legends champions are great champions. Both have their strengths, weaknesses, and counters. In League's current meta, Sett usually loses when playing against Trundle, with a 48.8% win rate. Therefore, Sett makes a poor counter for Trundle.
While Sett does have a lower winrate than Trundle, when they face off with one another, Sett also has a lower learning curve that makes him a less difficult character to pick up and master. You should be careful when picking Sett into Trundle.
Moreover, Sett also has only a small amount of CC and other utility, a similar amount to Trundle. This makes her just as valuable during teamfights, especially when facing champions with a ton of burst damage.
While there isn't a single best champion for every situation in League of Legends, in Sett vs Trundle matchups, Trundle is the better champion with a lower win rate, less champion complexity, and a similar amount of utility to help out your teammates during teamfights.
Sett is a somewhat poor counter for Trundle. You will do well by focussing your tactics on keeping up your gold income and clearing objectives. If you do that, you should do very well as Sett against Trundle.
If you would like to truly master Sett in order to counter Trundle during both the early game and mid / late game phases of League of Legends, you should continue reading to learn a few extra tricks and insights into this matchup. If you listen to the build and stats displayed above, you will grow your win rate significantly and be closer to League of Legends pro players.
Sett often accumulates more CS relative to Trundle. Champs who typically don't earn much CS often don't have to have much CS to be effective, such as supports. These kinds of champions are capable of scaling properly off of their skills, stats, and first items alone. Yet, champs with a lot of CS, such as hyper-carries, usually need many items to be effective. In either situation, try to surpass the numbers reported on this page to do well.
The best items to use in your Sett versus Trundle build include Stridebreaker, Sterak's Gage, and Titanic Hydra. When Sett bought at least these three pieces in his build, he did a lot better versus Trundle than with many other commonly used item sets. In fact, Sett had an average winrate of 48.8% when playing against Trundle with this build.
To have the greatest likelihood of vanquishing Trundle as Sett, you should equip the Conqueror, Triumph, Legend: Alacrity, Last Stand, Unflinching, and Second Wind runes from the Precision and Resolve rune sets. Of all the rune sets players chose for Sett vs Trundle fights, this mixture of runes resulted in the greatest win rate. In fact, these runes averaged a 48.8% win rate overall.
By default, tips, statistics, and builds on how to beat Trundle as Sett are displayed for all skill levels combined. If you want to scope the statistics and builds to an individual rank, you should use the selection menu located earlier in the counter matchup guide.