General Simulation Works
ENES

Mumblemoor

Whisper in Mumblemoor and a corpse will repeat it.

1 to 8 players · Windows · In development

The game

Mumblemoor is a first-person dungeon crawler for one to eight players.

Create your adventurer and join your friends in a cooperative campaign that takes you through old barrows, damp cellars, haunted castles and dangerous caves. Death waits around every corner, and only the toughest heroes will make it home to enjoy their fame, glory and riches.

Classic old-school rules, heirs of the dungeon-crawl games of the early 1980s.

Play together

  • One to eight players. Best with friends.
  • Built-in proximity voice chat.
  • The host sets the house rules, such as friendly fire or the rules for critical hits and fumbles.
  • Hardcore "rules as written" options for the grognards among you!

The rules

  • Seven classes: fighter, cleric, magic-user, thief, dwarf, elf and halfling.
  • Descending armour class and THAC0. Enjoy explaining it to your partner for the fourth time.
  • Combat in chaotic real time.
  • Light burns out, food runs low, and one slip can leave your ghost haunting the rooms of the Guttering Candle.

Technology

Mumblemoor runs on the Lucerna Engine, a custom engine written in Rust for this game.

  • Software rasterizer. Every frame is drawn on the CPU, squeezing the most out of AVX2 and FMA.
  • Analytic solids. People, monsters and objects are made of mathematical formulas that the engine traces per pixel.
  • XPBD cloth. Capes, tabards, robes and curtains: the fabrics are simulated with extended position-based dynamics.
  • Deterministic simulation. Each client builds the level from the same seed.
  • Music. An original soundtrack composed in MIDI and played with the GeneralUser GS soundfont.

Pictures

  • A party of heroes fights skeletons on a chequered crypt floor.
    A party fights skeletons in a crypt hall.
  • A party of heroes fights orcs and an ogre in a swamp beside a ruined tower.
    A party meets orcs and an ogre in the swamp.
  • A first-person view of a staff and a hand, with sleeping goblins ahead in a dark cave.
    First person: a hero creeps up on sleeping goblins.
  • A yellow paper map in a crypt hall that shows part of one dungeon floor.
    The partial map of one dungeon floor.
  • A goblin king with a sceptre and five goblins in a dark cave.
    The goblin king and his court in a cave.
  • The wooden hall of an inn with red banners, candelabras and a bard with a lute.
    The hall of the inn, where the bard Lutey Lou plays.

Facts

Platform
Windows x64
Players
1 to 8
Input
Keyboard and mouse
Processor
Needs AVX2 (Intel Haswell from 2013 or later, AMD Ryzen). 6+ cores recommended.
Languages
English and Spanish
Status
In development, Early Access planned for December 2026
Studio
General Simulation Works
Distribution
Steam

Mumblemoor uses Open Game Content under the Open Game License v1.0a. Licence and copyright notices

Community

Join the Mumblemoor Discord