Dogroth Caldera (a.k.a. Noxious Caldera) appears on the main wilderness map of Maj'Eyal at character level 20 or higher, but not in all games. In each game, only one out of Dogroth Caldera, Sludgenest, the Old Conclave Vault, and (if Forbidden Cults is enabled) the Scourged Pits will appear. This is chosen randomly, unless you are a Yeek and have not yet unlocked Solipsist, in which case this zone will always be chosen. A dialog "You feel a tremor in the ground for a few seconds and it disappears..." indicates this zone's appearance.
Warning: If the player restarts the same character after death, or overwrites an existing character with a new one, none of these zones will spawn.
The first level features a winding tunnel which leads eastward. If your character needs to breathe, there will be a timer counting down 600 game turns, due to the noxious fumes of the caldera. If this timer reaches 0 you enter a soft dream. If you complete the objectives within the dream successfully, you will return to the Caldera with a reset timer, and you will be invulnerable for 4 turns. If you fail your objectives and die within the dream, you will still return to the Caldera but will suffer damage equal to 2/3 of your current life over 4 turns. This damage can be absorbed by damage shields. Which dream the fumes will trigger is random. After exiting a dream, the timer will restart.
The second level has a timer counting down 60 turns. This timer does the same thing as the previous one. The level is roughly circular in shape; you begin on the western edge. On the eastern edge, there is an altar of dreams, and a boss named Mindworm. When Mindworm dies, the fumes become less poisonous, permanently stopping the timer. The altar of dreams can be used to voluntarily enter a dream, even if your character does not breathe. The altar will first trigger the dream of vulnerability, then the dream of loss, and will then alternate between the two. Unlike dreams triggered via the fumes, you will not receive any invulnerability or take any damage after a dream triggered via the altar.
Due to the danger of failing a dream while fighting in the Caldera, it can be useful to wait out the timer in safety, quickly fail it on purpose, then heal up and engage the next group of enemies before the timer counts down again.
These dreams do not give any rewards for your current character, but they are necessary for the Solipsist class unlock. Players may want to kill the Mindworm quickly to stop the timer and then enter dreams using the altar instead, to reduce the risk from taking damage.
Prior to version 1.3.0, failing the altar's dreams could instantly kill you (probably a bug).
Prior to version 1.4.0, you could not unlock Solipsist using the altar.
To unlock Solipsists, you need to complete two different dreams: the dream of loss (sometimes called the wife dream or lost man dream) and the dream of vulnerability (sometimes called the mouse dream). These dreams can be completed before killing Mindworm or by using the altar. Tips for both dreams are below.
As soon as you successfully complete both dreams, you will get the achievement and the unlock. It is recommended to kill Mindworm, since he drops boss quality loot.
Dream of loss
The wife dream has you taking control of the "Lost man". The objectives of the dream is to talk to the different yeeks in the rooms. All but one of them will transform into ghouls, which you have to kill. To do so, you must use the "Dreamstones" scattered among the rooms. These heal you for about 100HP. Hit an enemy until you are low, run to a stone, rinse and repeat. Dreamstones disappear after being used once, but there are a large number of dreamstones available.
Eventually you will find your wife, represented by an orc broodmother sprite. The same tactics apply to her. After you have slain her, step through the portal to return to the Caldera.
The lost man starts out with three unassigned stat points, which you can assign by pressing 'p'. Additional points in strength will increase your damage and end the fights quicker.
As of version 1.2.3, this dream can become bugged with no broodmother spawning, and thus no exit. If speaking to a Yeek results in it disappearing into thin air, then the dream is likely to be bugged. In this case, you may bind a hotkey to your melee attack and punch yourself to death to exit the dream.
Dream of vulnerability
The mouse dream is far more difficult; it has you taking control over the "frail mouse". The objective of the dream is to escape to the exit portal, most commonly found in the lower right corner but sometimes on the far right bottom corner.
The mouse starts out with three unassigned stat points, which you can assign by pressing 'p'. Putting all three points into Con is a huge help; it more than doubles your hit points, allowing you to take a couple of unlucky hits from cats before dying.
While exploring, keep an eye out for mouse holes. These look like trails through the woods (similar to the Old Forest or Trollmire's entrances) but can be hard to make out due to the dream distortions. Stepping on a mouse hole will teleport you to the other side, leaving any cats behind and (usually) allowing a moment of peace to re-stealth and rest up your cooldowns.
Your rodent's success depends upon repeated successful disengagements. Start out by activating Stealth and scouting your surroundings, turning back IMMEDIATELY when you encounter a cat in your path. Once you've evaluated your predators' locations and have as much of the map revealed as you safely can, you can get to work baiting the cats out of your way. To do this, remain stealthed in front of a cat at medium to long range until it notices your position and starts walking towards you. Next, lure the cat 3-7 tiles deep into a dead end (or pathway you no longer need). When the cat is close enough to attack you, pop Evasion and reposition yourself so that you are within 7 tiles of the pathway you want to exit towards. Finally, activate Hide in Plain Sight to lose the cat's focus, then Leap towards the corner of your escape path and walk out of the cat's vision range as quickly as possible (usually about 2 turns). Done properly, you will consistently move cats out of your way with minimal risk.
Version 1.0.0 glitch (Spoiler Alert):
- If you manually save your game within a dream and are not standing in the tile your Lost Man/Mouse originally spawned, your main adventurer will magically appear in your original spawn location. Your adventurer cannot be controlled, move, or use abilities, but they will use basic attacks against anything that attacks them. In the mouse dream, you may outright kill the level 1 cats by dragging them into your adventurer, which may be useful if your starting location is considerably hostile.