Universal Tower Defense X: Trait Reroll Calculator

The UTDX trait reroll system is one of the most important progression mechanics in Universal Tower Defense X. Every unit can hold one trait, and the difference between a B-rank trait and an S-rank trait like Ruler or Eternal can mean the difference between clearing and failing endgame content. The 277 pity system ensures that every player eventually receives an S-rank trait — but understanding the underlying probability helps you plan your resources. With a base S-rank trait drop rate of 0.3% per roll, you have roughly a 14% chance of getting one within 50 rolls, a 26% chance within 100 rolls, and a guaranteed drop at 277. This calculator helps you visualize those odds and make informed decisions about when to spend your trait reroll tickets or gems.

Choosing the best trait for your unit depends on your team composition and game mode. For most players pushing tower defense stages, Ruler is the consensus pick — it provides a flat damage multiplier that synergizes with every DPS unit in the game. Eternal is the mathematically superior choice for infinite-scaling modes where fights last beyond wave 20, as its stacking mechanic compounds over time. Fission sees niche use in AoE-heavy compositions. Regardless of which S-rank trait you target, always prioritize rolling on your strongest Mythic carry first. The trait reroll pity counter persists across sessions, so there's no rush — but there's also no reason to waste rolls on units you'll eventually bench. Use this UTDX trait reroll calculator to track your pity progress and calculate exactly how many rolls you need for a comfortable chance at an S-rank trait.