Coin flip guide
Why does a coin land on heads or tails?
A coin has two broad faces designed to rest flat. After its motion settles, gravity and its shape make one face the stable landing position.
Motion and landing
A tossed coin spins and tumbles until friction and impact remove its energy. It eventually rests with one face upward.
Why edges are rare
Coins can land on an edge in unusual conditions, but the edge is not a stable resting position on ordinary flat surfaces.