DM-300 infobox
Spawns in 15 (Caves)
Walk speed 1 tile per turn
Health 200 HP
Dodge 18
Armor 10
Resistant to Grim weapon
Scroll of Psionic Blast
Immune to Toxic gas
On damage Nothing special
Range Melee
Accuracy 28
Damage 18 to 24 (21 ±1.46)
Attack delay 1 turn per attack
On hit Nothing special
Max level
30 for XP
32 for drop
Experience 30 XP
Drops Skeleton key (always)

Ring of Thorns (1/3)

The DM-300 is the boss of Caves.


DM-300 gif
This machine was created by the Dwarves several centuries ago. Later, Dwarves started to replace machines with golems, elementals and even demons. Eventually it led their civilization to the decline. The DM-300 and similar machines were typically used for construction and mining, and in some cases, for city defense.


  • When noticing you, DM-300 yells: “Unauthorised[sic] personnel detected.”
  • DM-300 emits toxic gas around it.
  • Every time DM-300 walks, it makes an avalanche on a random square around it. This avalanche can damage and stun you.
  • DM-300 can regain health very quickly when standing on triggered traps.
    • This can be seen when the message says "DM-300 repairs itself!"
  • When dying, DM-300 yells: “Mission failed. Shutting down.”

The Fight

The room where DM-300 is found is very large and donut-shaped. The entrance will be collapsed when entering the room. Scattered around the room are triggered traps. DM-300 has no ranged attacks.

It takes time for the toxic gas cloud to spread each time the DM-300 moves, so the simplest strategy to avoid the gas is to move one square away from it each time the gas spreads onto you. The DM-300 will chase you, moving back into striking range. Since it moves at the same speed you do, this will give it no extra hits. Because of the pattern by which gas spreads, you'll have an extra turn if you move away from the DM-300 diagonally.

As with other bosses, you can slow, paralyze, or freeze the DM-300 to reduce its chances to hit you (although this will prevent the above strategy for avoiding the toxic gas). Unlike other bosses, it can't be slain with a Potion of Toxic Gas.



  • If you die at depth 15 with an Ankh, after the floor resets, DM-300 will now be called "DM-350".


Update Change
0.3.5 Changed: All bosses are now resistant to Toxic Gas & the Grim enchantment
0.5.4c BUG: Stopped dropping Ring of Thorns
1.6.0 Fixed: Non-obtainable Drop bug
Community content is available under CC-BY-SA unless otherwise noted.