The goal: be the first to get rid of all your cards. There are no turns — both players play at the same time. Speed wins.

Your board: you have 5 piles (only the top card is face up) and a face-down spit pile in reserve. Two center piles sit between you and your opponent.

Playing: drag any face-up card onto a center pile if it is one rank higher or lower than the card showing. Suits don't matter. Aces wrap: K–A–2 all connect.

Gaps: if one of your piles is empty, drag another face-up card into the gap to uncover the card beneath it.

Stuck? When neither player can move, both hit SPIT! (or press Space) and a fresh card flips from each spit pile onto the centers.

The slap: the instant a player clears all 5 piles, both players race to slap a center pile (click it). You want the smaller pile — you take it into your deck for the next round. The other player takes the rest.

Winning: rounds repeat with fewer and fewer cards. Clear your board with no spit pile left and you're out of cards — you win.

Controls: drag cards to play, or tap a card to select it then tap a center pile to play it there (great for touch screens) · click a center pile to slap · Space or the red button to spit.

Keyboard shortcuts: 1–5 select a pile · Z / X play to left / right center pile (or slap in slap mode) · Esc deselect.