Gloomhaven is a game with a persistent and changing world that is ideally played over many game sessions. After a scenario, players will make decisions on what to do, which will determine how the story continues, kind of like a “Choose Your Own Adventure” book. Playing through a scenario is a cooperative affair where players will fight against automated monsters using an innovative card system to determine the order of play and what a player does on their turn.
Each turn, a player chooses two cards to play out of their hand. The number on the top card determines their initiative for the round. Each card also has a top and bottom power, and when it is a player’s turn in the initiative order, they determine whether to use the top power of one card and the bottom power of the other, or vice-versa. Players must be careful, though, because over time they will permanently lose cards from their hands. If they take too long to clear a dungeon, they may end up exhausted and be forced to retreat.