The game of Efni uses Icehouse pieces and (a subset of) a Fluxx-deck.

The Fluxx-cards are shuffled and dealt, face-down, to form a playing board. Icehouse pieces are distributed over the play area (exact distribution depends on the number of players). Players take turns to move and reveal cards.

The object is to capture sets of cards by occupying those cards with your own pieces. Points are scored for the number of Goals and Keepers captured with goals worth ten times the keepers.