Input remapping
Letting players reassign which physical buttons trigger which in-game actions, decoupling the game's logic from fixed hardware keys.
Early games hard-coded controls — jump was always the spacebar — which excluded left-handed players, unusual controllers and anyone with a disability. Remapping inserts a layer between raw device input and game actions: the code asks "is the Jump action pressed?", and a lookup table says which button that currently means.
Modern input systems (Unity's Input System, Steam Input, SDL's game-controller database) build the whole engine around named actions and binding sets, so a game supports keyboard, gamepad and exotic devices for free. It is now considered a baseline accessibility feature, and storefront certification often requires it. The same indirection enables control schemes that switch by context — on foot versus in a vehicle.