- "Create a pillar of ice from a water surface. Builds ice pillars that are very stable. These pillars can be used as stepping stones or as obstacles. Use Cryonis on an ice pillar to break it."
- — In-game description
The Cryonis Rune is an item from The Legend of Zelda: Breath of the Wild. It is a Rune ability for Link's Sheikah Slate unlocked in Keh Namut Shrine. It can be used to create large ice pillars that Link can climb. Other than climbing on top of the ice pillars, they can also be used as blocks to force open closed doors, stop doors that open and close rapidly, or shield against enemy attacks. Ice pillars can be created vertically from the ground or horizontally on waterfalls. Up to three pillars can be active at once; if Link creates a fourth pillar while three pillars are already active, the first pillar (by chronological order of creation) will disappear. While Cryonis is active, Link can also manually destroy an active pillar.
According to the Sheikah Slate Manual in the Hateno Ancient Tech Lab, the pillars can also be used to cut the line of sight of a Guardian's search beam (laser sight) which Link can create in water to hide behind. Additionally, Link can use Cryonis Pillars to lift up floating objects out of the water which is especially useful for accessing and opening wooden Treasure Chests occasionally found floating in water.
Cryonis is also used by Divine Beast Vah Ruta, Waterblight Ganon, and Calamity Ganon during their battles against Link. In these cases, they create blocks or spiked balls of ice to use as projectiles, which can be destroyed with a well-aimed arrow or by the use of Link's own Cryonis rune.
Although the Cryonis pillars are made of ice, they do not lower the temperature of the surrounding air like ice-based items and weapons do, nor do they have a freezing effect on materials placed on or near them.
The word "Cryonis" comes from the Greek cryo or cryos (κρύο) which means "icy cold".