When a Pokémon with Emergency Exit drops below half of its full HP in battle, it will flee in wild battles, or switch out in Trainer battles. It can only activate when a Pokémon's HP falls from above half to below half; if it does not activate at that time, it will not activate at all (unless the Pokémon with this Ability restores HP).
Emergency Exit will not activate if the Pokémon's HP falls below half due to hurting itself in confusion, hail, sandstorm or using Substitute or Belly Drum, but it will activate if the HP falls below half from Spikes or Stealth Rock damage. If the Pokémon falls below half HP and immediately consumes a Sitrus Berry or other Berry to rise above half, Emergency Exit does not activate, but if it falls below half and recovers back above half from a Shell Bell, Emergency Exit will activate even after the Shell Bell recovery, and cause the Pokémon to retreat.
Emergency Exit will not activate if the Pokémon's HP falls below half by a move affected by Sheer Force.
It will activate only after the last hit of multi-strike moves, even if the HP of the Pokémon with this Ability drops below half before the last hit. If this Ability activates due to being hit by U-turn or Volt Switch, the user of that move will not be switched out. This Ability will not activate if the Pokémon's HP falls below half while it is in the air during the semi-invulnerable turn of Sky Drop.