Slay the Spire is an adventure battle card game. You play one of four characters attempting to ascend a spire of multiple floors. You fight enemies and bosses by playing cards you have collected. You gain new cards as rewards from combat. With 100's to collect you can build a strategic deck of cards that complement each other.

When your run through the game ends, you start again, but with extra cards you may have unlocked. Returning to try again has the same progression by the floors and enemies will be different.

Along with basic attack and defence, cards are colour-coded cards tailored to your chosen character. In combat you play cards in turn, choosing any combination of cards as long as you have the required energy to pay for them. The key is not only picking your best cards but observing your enemy (and hovering over them for more information) to determine how they may attack and consequently how you need to counter.