Bad Luck

Bad Luck (Japanese: あくうん Bad Luck) is an ability created by for Generation VI.

In battle
Bad Luck prevents the foe from scoring a critical hit.

Outside of battle
Bad Luck lowers the encounter rate of the rarest Pokémon in a given area to 5% (or 1% if it is already 5% or less) and raises the encounter rate of the most common Pokémon.

Trivia

 * All of the Pokémon with this ability are part Dark-type.
 * Bad Luck has the exact same effect as the Battle Armor and Shell Armor abilities. However, its description implies that it directly inhibits the foe's ability to score a critical hit, rather than protecting the Pokémon against critical hits that would normally occur, as is the case with Battle Armor and Shell Armor.