Clank! is a deck-building game. Each player has their own deck, and building yours up is part of playing the game. You start each of your turns with five cards in your hand, and you'll play them all in any order you choose. Most cards will generate resources, of which there are three different kinds:
Every time you acquire a new card, you put it face up in your discard pile. Whenever you need to draw a card and find your deck empty, you shuffle your discard pile and turn it face down to form a new deck. With each shuffle, your newest cards become part of a bigger and better deck! Each player starts with the same cards in their deck, but they’ll acquire different cards during their turns. Because cards can do many different things, each player’s deck (and strategy) will become more and more different as the game unfolds.