Why Is Ice Slippery and How Is the Blade of An Ice Skate Able To Glide On Ice With No Friction?

One simple reason why ice is slippery is that pressure and friction from shoes or skates can melt a very thin layer at the top of snow or ice.

It then forms a watery lubricant between ice and skate (good) or ice and shoe (bad).

Skis also glide on a layer of water.

The process by which ice melts under pressure and almost immediately freezes again when the pressure is off is called regelation.