Biomes are the different areas within Dead Cells which players must progress through.[1] There are currently twenty-five biomes, with plans to add more.[2]
Within each run, biomes are procedurally generated within the confines of that biome's set parameters. This puts the focus of gameplay on adaptation rather than memorization, while maintaining each biome's distinct feel.[3] The order in which you'll encounter biomes, and the general location of their exits, are predetermined.
Excluding boss biomes, each biome always contains a shop and at least one treasure chest.
After exiting each biome, the player will enter the Collector's room. Here, they can turn in blueprints, spend cells, enter Timed and Perfect Doors if they met the requirements and replenish their health and health potions. Time spent in treasure chests, shops, lore rooms, and the Collector's room does not count towards Timed Doors. You will know if you are in one of these rooms if there is a [Pause] above the timer.
Note: scaling of enemy and trap stats with tiers operates somewhat differently compared to scaling of player damage and health with Stats - though damage and health initially scale exponentially using bases of 1.09 and 1.08, respectively, there are also additional factors in the code called "scale multipliers per tier" with values of 0.55 and 0.12 for damage and health, respectively. It is not yet known how these modify the exponential formulas to produce final enemy and trap stats.
You will also find in many Biomes a set of doors with up to five dotted circles on them, in random spread-out locations. These can only be unlocked once you have obtained the necessary number of Boss Stem Cells that are only obtained by doing a complete run, and unlock further challenges.
Cavern Key Door - The big door at the start of the biome. Contains the Cavern KeyRotG and Homunculus Rune is required to get it. (The Hand of the King must have been beaten at least once)
Garland KeyRotG: Gives access to the 4 BSC door which contains the blueprint of Festive OutfitRotG. Look for a vine passage in the ceiling, often near a shop.
Castle Key Doors: They are 6 doors of 3 different colors, 2 doors each. Each 2 doors lead to an extra section of the biome, which offers an Elite enemy fight and a Castle Key as reward.
Keys:
Castle Key: 3 in total. 2 are required to access Throne Room, while the 3rd gives access to blueprint of Boomerang and a Scroll of Power. Dropped by the three Elite enemies in each of the Castle Key doors.
Doors: There is a locked door blocking the exit to the Throne Room requiring the Distillery Key.
Keys:
Distillery Key: Gives access to the Throne Room. Can be found behind a destructible wall, which can only be destroyed by deflecting a nearby exploding barrel or by using the Barrel Launcher.
Technically inaccessible stage, entrance was behind the door that required 5 boss cells to open in the Graveyard. If accessed via modifying the boss cell counter with third-party tools, it could be seen that it had the same 'darkness' mechanic as the Forgotten Sepulcher. Only enemies present in the stage appeared to be Cannibals. The enemy tier appears to be absurdly high. The majority of the stage was locked behind a door that required a key (simply named "Key") to open, which can't be spawned even by third party modifiers
An old ending point of a run that persisted until the 1.0 update came around. It would be accessed after defeating the final boss of the game, which at first was Conjunctivius, then the Time Keeper, and finally, the Hand of the King. It used to have the Fisherman NPC right next to a boat, who would impale the Beheaded with a tentacle to let the player start a new run. Later that was changed to a "Work in Progress" sign and a tube, through which the Beheaded would crawl to go back to the Prisoners' Quarters.
Architect's Key.
