Quick answer
A trait is attached to one unit instance and a reroll replaces the current trait. Save Trait Crystals for units with long-term roster value, then target effects that reinforce the unit's actual role.
Trait basics
A Trait is a persistent modifier attached to one unit instance. The current research snapshot places the reroll machine in the lobby Upgrades area and lists one Trait Crystal as the normal reroll cost.
The replacement rule
Rerolling replaces the current Trait. You do not keep a library of past results, and the lost instance cannot be restored by choosing it from a menu. Treat every click as a resource and replacement decision.
Choose by unit role
Damage carry
Prioritize effects that improve the unit's real damage cycle: useful damage, attack speed, range or scaling interactions. A large-looking stat that does not fix the unit's bottleneck may be worse.
Economy
Judge an economy trait by how quickly it repays its cost and whether the mode is long enough to benefit.
Support and control
Utility units may value range, timing or uptime more than direct damage. Use the trait that improves the effect the team brought that unit to provide.
Safer reroll plan
- Confirm the unit will remain in your team.
- Define one primary role and one acceptable secondary role.
- Decide which existing results are “good enough” before rolling.
- Keep a reserve instead of spending the complete Crystal balance.
- Recheck trait probabilities after patches before making probability claims.
How to get more value
Redeem current codes before rolling, progress modes that award upgrade resources, and avoid optimizing temporary starters. A balanced team with sensible traits is usually more useful than one perfect carry surrounded by unfinished roles.
Frequently asked questions
Does rerolling keep my old trait?
No. The current trait on that specific unit instance is replaced, so stop before rerolling a useful result.