Backgammon

Five thousand years old, and the only game here where luck and skill are genuinely mixed rather than taking turns. You roll two dice and move two checkers. A better player wins most of the time but never all of it, which is why people come back to this one for decades rather than weeks.

The rules are the full ones, including the two that casual versions skip. A checker sitting alone can be hit and sent all the way back to the start, and while you have one on the bar nothing else you own may move at all. And you must play both dice if there is any order that lets you, and if only one can be played it has to be the larger. That last rule changes who wins games, so the board works out what you are allowed to do and offers you only that.

There is no doubling cube. It is where the real depth of backgammon lives, and it is also where a new player drowns, so it is left for later rather than switched on by default. Games are still scored properly: an ordinary win is one point, a gammon is two, and a backgammon is three.