Friday is a deck-building game in which you try to add good cards to the deck and get rid of the bad ones. With this deck you fight against the dangers. If you defeat one danger (card) you will add this card to your deck (good). If you lose against a danger you lose some health tokens but you can get rid of the cards you lost with (generally weaker cards). If you have no health tokens left and lose one more health point: game over; if you defeat both pirates you win.