Tenacity

Tenacity controls debuff resistance. When an enemy ability tries to apply a debuff, the game rolls: ability base chance + attacker Potency − target Tenacity. If the resulting probability beats a random roll, the debuff lands. If not, your character "Resists" the effect. Higher Tenacity means more resists.

Tenacity comes from mods (Tenacity primary on Cross slot, Tenacity secondaries on any slot), kit values (tanks and support characters often have high innate Tenacity), the 2× Tenacity mod set (+20%), and lead Zetas that grant Tenacity to allies. Stacking it on tanks is standard practice because they're the primary target for incoming debuffs.

However, "Tenacity Up" buff is more important than raw Tenacity for endgame play. Tenacity Up grants 100% resistance to incoming debuffs (with rare exceptions in modern kits), making any character effectively debuff-immune while the buff is active. Many leaders grant Tenacity Up on allies automatically each turn — Padme Amidala's "Roger Roger" lead Zeta is the classic example.

Tank characters that excel with high Tenacity include Baze Malbus (becomes nearly untouchable while Taunting), Jolee Bindo (Tenacity stack with his Unique), and Mother Talzin (Nightsister support that keeps the squad alive vs debuff-heavy enemies). Pair Tenacity with high Health to create units that simply refuse to die.