Highest card takes both. Ties mean war.
The simplest card game there is. There are no decisions at all — the deal decides the winner, and the game just takes a while to admit it.
A 52-card deck split evenly, 26 cards each, face down. Aces are high.
Both players turn their top card face up at the same time. The higher card takes both, and they go to the bottom of the winner's pile. Suits are ignored.
If the two cards are the same rank, it is war. Each player puts three cards face down on top of their card, then turns up a fourth. The higher fourth card takes the whole pile — ten cards at once.
If those cards tie as well, the war repeats.
A player with too few cards to complete a war puts down whatever they have and turns up their last card. Losing it loses the game.
The game ends when one player holds all 52 cards. This can take a very long time — some deals never resolve at all, because the pile keeps circulating in the same order.
For a game that finishes, agree a time limit or a number of rounds in advance and count cards at the end.
Deal seventeen cards each, discard the last one, and the highest of three cards takes the trick. Two-way ties go to war between the tied players only.