Cardoku is a head-to-head Sudoku game using Tech Decks, modernized decks of playing cards. Players divide into two teams. Each turn, players/teams draw a card, then play a card. If they have no cards in their deck, they have additional options open to them. They can move a card or swap two cards. The game ends when either all players have no cards in hand or there are no more possible plays. Players score points when they complete a row, column or 3x3 box.