Three expired gaming-mechanic patents: Crazy Taxi's direction arrow, Namco's loading-screen minigames, and Eternal Darkness's sanity system
Three mechanics that used to carry a license shadow and don't anymore: the floating direction arrow, the playable loading screen, and a game that lies to you about its own state.
The already-free arsenal · Sega / Namco / Nintendo (Silicon Knights) · All three already public domain
US6200138B1 — Sega's patent on the floating arrow that points toward your next objective, introduced in Crazy Taxi — expired in 2018. It's such a basic piece of UI vocabulary now (way-point arrows are everywhere) that it's easy to forget it was once somebody's claimed invention.
Namco's patent covering playable minigames during loading screens expired in 2015. The idea of turning dead loading time into a small game is free to use without a licensing conversation.
Eternal Darkness: Sanity's Requiem's sanity-meter system — the mechanic that triggers fake glitches, fake save-deletion prompts, and fourth-wall-breaking tricks as a character's sanity drops — was patented by Silicon Knights and later held by Nintendo. That patent has expired; the toolbox of 'the game lies to the player about its own state' is public property now.