Service locator
A registry that hands out a service through its interface, sparing the caller from knowing or constructing the concrete implementation.
Game engines are full of global systems — audio, logging, file access — that nearly everything needs but nobody wants to thread as an argument down the whole call chain. A service locator offers one central lookup point: Locator::audio()->play(...). The concrete class can be swapped out, even for a silent null service during tests.
The pattern is contested. Critics (Mark Seemann among them) call it hidden global state that conceals dependencies, and prefer dependency injection instead. In games it often wins anyway on sheer simplicity, and on the fact that an engine rarely swaps its core systems mid-run.