In Culdcept, the player takes on the role of a Cepter. Cepters are beings that have the ability to use magical cards to summon creatures, cast spells, and perform various other feats of wizardry. As players advance through the game, they earn additional cards that they can use to create customised "decks" (of 50 cards) with which to better defeat their foes.

The initial 1999 PlayStation release, Culdcept Expansion, has an additional four maps for a total of 14, and also contains 360 cards but 10 of them have been replaced with new ones for balance reasons, as well as the ability to load custom maps from a memory card. Your objective is to have collect enough magic points (MP) before your opponents do and reach the castle. You do this by controlling areas on the board with creatures that you summon. Players (called Cepters) affect each other by attacking each other's creatures with their own. Players cannot directly attack each other, but can cast spells on each other. If you lose a battle on an opponent's square, you must pay them (rent) as MPs.