Dungeon Crawler

Dungeons are removed from the game as a state-based action.

You can only move forward (well, downward) in a dungeon, never backwards or sideways.

To venture into the dungeon, a player moves their venture marker into the next room of the dungeon they are currently in. If they aren't currently in a dungeon, that player instead chooses a dungeon card from outside the game, puts it into the command zone, and moves their venture marker onto the first room.

Dungeon cards are not part of a player's deck or sideboard. In both constructed and limited formats, players can use any dungeon card when they venture into the dungeon.

Once you resolve the last room ability of a dungeon, that dungeon is now completed and is removed from the game.

Choosing the dungeon or room to venture into is part of resolving the venture into the dungeon keyword action. Once that choice is made, players may not respond until after the appropriate room ability has triggered.