Deckbuilder

Deckbuilder describes games where a player's deck is not fixed at the start but assembled through play — cards bought, gained, or crafted during a session join a shared draw pile, so a player is never just choosing what to play from a hand, but shaping what hand they'll be dealt next. Dominion is the mechanic's origin point: a market of card piles the whole table shares, where the winning move is often not the flashiest card but the one that thins the deck of the weak starting cards clogging every draw.

That thinning-versus-bloat tension is the genre's central puzzle. Every card added to the deck is a future draw diluted, so a deckbuilder rewards restraint as much as acquisition — a lesson players used to more-is-better RPG inventories often learn the hard way. When a deckbuilder's cards start generating resources that buy more powerful cards, the mechanic shades into Engine Building; the two overlap constantly but aren't synonyms; a deckbuilder without any snowballing engine (pure thinning and curve-smoothing) is still a deckbuilder.

Roguelike Deckbuilder is the genre's most consequential mutation: bolt permadeath and a single linear run onto the deckbuilding chassis, as Slay the Spire did, and the thinning problem gets sharper stakes — a bloated deck doesn't cost you the next turn, it costs you the run.

Deckbuilding is also worth distinguishing from Worker Placement, another economy-through-scarcity mechanic: a deckbuilder's scarcity lives in what you'll draw, a worker placement game's scarcity lives in which action-slot is still open when your turn comes.