Royal Cotillion

Royal Cotillion is two decks arranged as a formal dance: a Ladies' side of twelve cards and a Lords' side of sixteen, with eight foundations between them built from the Aces and the deuces of each suit.

The foundations build in twos, skipping every other rank, which gives the game its distinctive rhythm — at any moment each foundation wants a card two ranks up, so most of what you are looking at is useless to it. The asymmetry between the two wings is the real mechanic: one refills from the waste and one never does. Elegant to look at, austere to play, and unforgiving with only a single pass through the stock.

Two decks, and eight foundations: the Ace and the deuce of every suit. Each builds up by suit in twos rather than ones, so the Ace of spades is followed by the three, five, seven and so on, wrapping round past the King. The layout has two wings — a Ladies' side of twelve cards in four columns of three, and a Lords' side of sixteen in a four-by-four grid. Lords' cards are refilled from the waste as you play them; Ladies' cards are not replaced, so that side only ever shrinks. No cards may be built on one another anywhere, and the stock passes once.

The two wings behave completely differently and that is the whole game. The Lords' side replenishes, so playing from it costs nothing and keeps fresh cards coming; the Ladies' side does not, so every card taken from there permanently exposes what is underneath. Work the Lords' side hard and treat the Ladies' side as something to open deliberately. Because the foundations skip every other rank, half the deck is irrelevant to any given foundation at any moment — knowing which half saves a lot of hunting. One pass through the stock means there is no recovering from a missed card.