Skill failure

A skill that fails is prevented from completing, this is not technically considered an interruption from a game mechanics perspective, however. Skill failure occurs usually at the end of the skill's activation time. It has three properties:
 * 1) The skill has no effect.
 * 2) The skill's cost (energy, adrenaline, exhaustion) is forfeited.
 * 3) The skill does not need to recharge (unless it has been disabled) and can be used again immediately, unlike the effect of knockdown or true interrupts.

Causes

 * A skill fails at the end of its activation time if:
 * The target has died
 * The target has become invalid due to an "Invalid Target" effect
 * the skill has become disabled
 * Most Assassin attacks have prerequisites to work. If these are not met, the attack will result in a fail
 * Certain skills explicitly cause failure, either at the end of the activation time (e.g. Mark of Subversion) or immediately upon trying to activate a skill (e.g. Spell Breaker)
 * Cancelling a skill can also be viewed as causing immediate failure

Related articles

 * Disable skills quick reference
 * Action prevention skills quick reference
 * Interrupt
 * Interrupt skills quick reference