Nintendo

Neither Resident Evil nor Silent Hill, this system from one of the best GameCube games is now part of the public domain

Eternal Darkness’ innovative sanity system is now in the public domain, paving the way for new games to push the boundaries of psychological horror.

Gabriel Huerta

Update: Apr 17th, 2025 03:48 CEST

One of the most important games of the GameCube era was Eternal Darkness: Sanity’s Requiem. It was one of the few horror titles in Nintendo’s lineup, and it came with an innovative system. The game, following the Lovecraftian inspiration, had a sanity system that played with the player’s mind. And now that system has been released to the public.

Eternal Darkness’ sanity system is now free to use

According to the Reddit community, the patent for this system is now part of the public domain due to the expiration of its renewal period. The gameplay mechanic was registered by Nintendo of America in 2000, but it expired in 2021. Without a renewal, the system is now freely available.

looks like Nintendo's patent on a Sanity system for a video game expired a month ago!
by u/DocMemory in gamedev

Virtual Legality legal expert Richard Hoeg explains that the sanity system is now freely available, though not all elements of the game are. “You SHOULD be able to use whatever elements of an expired patent are necessary to its use (as described in the patent),” video game legal expert and creator of the Virtual Legality podcast Richard Hoeg told Eurogamer. “But NOT anything that is not ‘necessary’ (graphics, perhaps some specific implementations - eg, sanity effects - as that’s artistic expression rightly protected by copyright).”

What made the sanity system special?

With good Lovecraftian inspiration, Eternal Darkness features a sanity meter so that as the character progresses—and fails—it drops, causing sanity to drop and the character to lose their mind. The game featured several events ranging from bleeding walls, laughter, and moving armors to fourth-wall-breaking elements such as the TV turning off, the volume turning down, or even the save file “corrupting.”

Despite this, with the upcoming arrival of Nintendo GameCube games on the Nintendo Switch 2, it would be wonderful to see this game once again, even if the legal situation that its studio has been facing makes it complicated.