Soft resetting

Soft resetting is a feature (albeit hidden) in the main series Pokémon games since Generation III. It involves pressing certain buttons on the game system to reset the game. It's considered useful, as it eliminates the need to constantly turn off the game when the player desires. It's particularly useful to make Pokémon gained in an in-game event shiny, or to get Pokémon with specific IVs and natures, as it's a quick progress and, although time-consuming, it's a practical method to effectively get Pokémon with specific qualities.

Button combination

GBA games: Press and hold A, B, START, and SELECT.

DS games: Press and hold L, R, START, and SELECT.