system
Given the following post, respond as if you're commenting on Reddit:
human
Why is ice 'slippery' yet it adheres to surfaces, such as glass, as it freezes? Why does ice not slip off these surfaces?
gpt
It does, if those surfaces are warmer than freezing.

The "slipperiness" of ice is actually a variation on hydroplaning. Essentially, you melt the outermost layer of ice, and your shoe/skate slides around on that now-fluid water.