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.
Frequently asked questions
Are these game-mechanic patents part of the trading corpus?
No. The gaming wing sits outside the 13,862-patent trading corpus the rest of the site is built on. These facts are tracked by hand from public patent and news sources, not pulled from our database.
Does a patent on a game mechanic stop others from making similar games?
A patent covers the specific system its claims describe, not a whole genre. Mechanics that predate the patent or differ from the claims may be fine; whether a specific design infringes is a fact-specific legal question. This isn't legal advice.
Can I use the expired ones freely?
Once a patent's term ends or it lapses, the claimed mechanic generally becomes free to implement without a license. Other rights may still apply to a specific game, and this is general information only.