Which Pokémon games introduced innate Pokémon abilities?

Pokémon Ruby and Sapphire introduced innate Pokémon abilities to the main series. These abilities give Pokémon species-specific effects that can influence battles, exploration, or other game mechanics.

Examples include Intimidate, which lowers an opposing Pokémon’s Attack when its holder enters battle, and Levitate, which grants immunity to Ground-type moves. Abilities can therefore affect strategy before a move is even selected.

Ruby and Sapphire were released for the Game Boy Advance in Japan in 2002 and internationally in 2003. They launched the third generation and added 135 new Pokémon, the Hoenn region, Pokémon Contests, and double battles.

Abilities are different from moves, types, and natures. A move is selected during battle, while an ability is an inherent property of a Pokémon. Some species can have more than one possible standard ability, and later games added hidden abilities and further effects. The original Ruby and Sapphire versions also differed from Gold and Silver by not using a day-and-night cycle, although they retained a clock for other events.