This game is based on the Chalice Dungeons in the video game Bloodborne - the ever-changing labyrinths and tombs carved out by the Great Ones beneath the fallen city of Yharnam, where horrifying creatures reside. Players compete to kill monsters and take their blood.
Bloodborne is about risk assessment with a bit of group thinking, inventory management, and tactical play. You start with a hand of basic weapons, which you get to upgrade to improve your fighting capabilities.
Each turn, one monster chosen at random attacks players, who fight back as a team, with everyone playing a card from their hand in order to kill the monster. Players collect blood from the monster based on how much damage they dealt. Monsters can fight back with exploding dice that can potentially deal lots of damage.
Players can fight as long as they want, but if they die in combat, they lose their progress. Players can opt out of fighting to bank their blood and save it permanently. Collected blood counts as victory points.