Etrian Mystery Dungeon is a collaboration title crossing the world of Atlus Co., Ltd. 's Etrian Odyssey series with the roguelike gameplay of Chunsoft 's Mystery Dungeon series. It features familiar character classes and skill tree mechanics from Etrian Odyssey alongside a labyrinthine approach to the randomly generated Mystery Dungeons.
The game takes place mainly in dungeons made up of randomly generated tile-based floors. For every action the player takes, including movement, attacking, and usage of items, all enemies on the floor will also take an action. Players can progress through the dungeons by finding the stairs located on each floor. Unlike most other Mystery Dungeon games, which use a linear dungeon floor structure, this game's dungeons feature multiple sets of stairs per floor that lead to divergent paths.
As you go further through the various dungeons, you'll be granted access to stronger enemies, materials, and equipment, bringing your guild closer to uncovering the mystery of Yggdrasil's dungeons. To protect the town of Aslarga, which acts as the player's main camp, it is necessary to build forts and keep watch for these monsters.
Gameplay involves exploring randomly generated dungeons, battling enemies, and managing resources while navigating through multiple floors with divergent paths.