Ice is a slippery material that can make it impossible to ascend a slope and can cause a player to lose their footing on a bridge. Ice can also be used to go faster than base movespeed. Ice also affects physics objects.
The speed boost provided by ice is amplified by the wind depending on the wind speed. If the wind speed is high enough, the avatar will continue to "slide" even after the wind has pushed the avatar off the ice.
Ice can be used to craft an Ice Bomb which, when detonated, will cover a small area with Ice. A tall pyramid made of ice, when built, will cover nearby surfaces in more ice. The spread of ice appears to be up to a 6x6 area. The ice will cover vertical surfaces within that area.