Stagger

Stagger is part of TERA's combat system. Stagger prevents player using any skills, attack or defense themself for a sub-second time. Stagger happens ie. when jumping down from high place or due certain attacks.

This allows certain classes (like Valkyrie) to stagger-lock opponents from using skills in PvP by repeatedly casting Combo Attack (auto-attack) which staggers opponent player. Stagger can also prevent players dodging or moving before next attack skill connects. Skill that player was casting when staggered is interrupted and goes to cooldown.

Risk of stagger depends on your Balance Factor. Generally classes wearing cloth armor have lowest Balance, and classes with Metal Armor and tanks (includes Warrior tank in Defensive Stance) highest.

There are certain skills that improve your balance. Priest is immune to knockdowns or staggers while casting Purifying Circle or slayer with Knockdown Strike, Whirlwind or Heart Thrust. Priest's Arise skill gives all allies a buff that doubles balance for few seconds. Also almost all shield skills prevent stagger while shield lasts.

Brutal Weapon Crystals (Increases damage to knocked-down opponents by X%.) also increase damage to staggered targets. In certain boss shield phases boss is counted as staggered after a successfully broken shield.