The blood moon in The Legend of Zelda: Tears of the Kingdom is one of the game’s creepiest moments. Scarlet clouds paint the sky and a ghostly aura reanimates monsters from the dead. The scene is among one of the scarier parts of the game, but beneath its red ooze, this event hides a practical application: The blood moon functions as a way to refresh the game’s memory use and stop Link from pushing the Nintendo Switch to its limits.
The regular (non-glitched) blood moon rises every 168 minutes, the equivalent to one week of in-game time. Once the cutscene plays, enemies in Hyrule respawn and Link gets a fresh batch of monsters to fight. Although waiting for the elapsed time is the more common method to experience a blood moon, it isn’t the only way. Players can force a blood moon scene by overloading the Switch’s memory. Fans have dubbed the phenomena a “panic moon” because the game uses the moon as a failsafe to stop things from crashing when players push the game’s memory usage to its limits.
In a previous article, Polygon spoke to MiztrSage, an expert builder from the Hyrule Engineering subreddit. In his work, the builder explained how the game itself can be a limiting factor in what can — or can’t — be built in the game. The builder explained to Polygon how the blood moon is actually used as a way to make up for the Switch’s limitations:
The game has a built-in memory ‘refresher’ which automatically triggers a blood moon once you start ‘pressuring’ the game with, for example, too many objects in Link’s vicinity. The blood moon then removes all the objects around you that caused this overload and resets enemies. All because the Switch is not powerful enough.
Players have documented a few ways to pull off the “panic moon.” In one, a player forced the event by firing several opal-fused arrows with a Lynel bow at a breakable rock wall; a Lynel bow fires three arrows at a time and the opals create a splashing water effect, so firing them at the wall quickly overloads the Nintendo Switch with animations and water effects. In other cases, people have triggered the blood moon with topaz-fused arrows, which result in an electrical burst upon landing.
Tears of the Kingdom is a technical marvel in many ways. Even seemingly “simple” tasks like building a bridge can present vast technical challenges to developers. For our report on the game’s bridge physics, a technical producer talked to Polygon about a particular bridge that can be towed across a lava pool. “The amount of dynamic objects is why there are so many different kinds of solutions to this puzzle in particular. There are so many ways this could break,” the producer said.
In a sense, the blood moon represents the pinnacle of Nintendo’s clever game development. It’s a sneaky but elegant way the developers mask the limitations of this otherwise awe-inspiring game. On a tonal level, the blood moon adds a creepiness to the game and develops the overall somberness of Hyrule post-Upheaval. From a gameplay perspective, the blood moon respawns enemies and can bring excitement back to the world. And on a technical level, the blood moon also saves the Switch from itself, preventing it from pushing too far past its limits. It transforms a limitation into a feature.