It's more like a two-party roll of a die with a practically infinite number of faces. If both rolls sum even, Alice wins. Otherwise, Bob wins.

Alice and Bob commit to their rolls by hashing them then making a future spend contingent on revealing the roll that produced the hash.

The trick is how to reveal both rolls without giving an advantage to the one who reveals second. This is the problem the protocol solves - through transaction setup and the newly-activated Script opcodes.