Dungeons in ToM consist of several layers utilizing full 3D space, each layer constructed from tiles. Layers can span to several thousand or more tiles in width. The maximum size is currently unknown. Layers can also be stacked in the same manner, with the limit being around several thousand stacks, but it's more likely that the average dungeon will have a more realistic number of layers.
The game will progressively get harder the deeper you go and the dungeon environment will change. You will be given the option of using bind points to respawn at so that you don't have to find your way through a maze to get back to where you were. Bind points may not be permanent, and they may have to be maintained somehow.
Dungeon walls can be destroyed by use of explosives, spells, or wall pounding AI. Paths can be carved through dirt and rock for the purpose of creating shortcuts, hiding places, mining, reconstruction, or just for fun.
The entire world is generated upon first entering a new dungeon. Players may enter any size when generation a dungeon. Rooms are pre-designed with combinations of tiles and connected randomly via an outward growing network of halls and rooms. Each room may split off into several hallways, and hallways that result in a dead end are removed. The dungeon is filled with controlled random elements as it generates, and progressively gets harder and changes environment the further it generates and the deeper the dungeon goes. Each dungeon area will be designated as a tier or progression point while generating so that quests and puzzles, keys/switches can be generated in a progressive order.
Video Example of Dungeon Generation in Real-Time: