Ultima Underworld II: Labyrinth of Worlds: 4 Open Source Clones Compared
UnderworldExporter and UnderworldGodot both state they need assets from Ultima Underworld 1 and/or 2, and UnderworldExporter's own known limitations specifically call UW2 'very buggy and not as feature complete as UW1,' with occasional save-loading glitches. Underworld Adventures, by contrast, describes itself as a project to recreate Ultima Underworld 1, and its documented limitation only concerns missing UW1 features — it isn't described as covering UW2's content. UnderworldExporter and UnderworldGodot are also directly linked: UnderworldExporter's README says its author moved development from Unity into the separate UnderworldGodot repository, which is newer but still pre-alpha and unplayable, while UnderworldExporter itself is now marked dead.
Comparison table
Availability
- Status
- Playable
- Platforms
- Windows
- Play in browser
- No
- Mobile
- No
Project health
- Development status
- Archived
- Last updated
- 3y ago
- Stars
- 340
- Contributors
- 2
- License
- MIT
- Engine
- Godot
Compatibility
- Requires original assets
- YesThe project requires original game files from Ultima Underworld 1 and/or 2 to function.

Availability
- Status
- Unplayable
- Platforms
- Windows
- Play in browser
- No
- Mobile
- No
Project health
- Development status
- Active
- Last updated
- today
- Stars
- 323
- Contributors
- 5
- License
- MIT
- Engine
- Godot
Compatibility
- Requires original assets
- YesRequires game files from Ultima Underworld 1 or 2; GOG versions must be extracted from the game.gog file.

Availability
- Status
- Semi-playable
- Platforms
- Windows
- Play in browser
- Mobile
- No
Project health
- Development status
- Active
- Last updated
- 2mo ago
- Stars
- 74
- Contributors
- 3
- License
- GPL-2.0
- Engine
- SDL2
Compatibility
- Requires original assets
- YesThe project recreates Ultima Underworld 1 using the original game files.

Availability
- Status
- Semi-playable
- Platforms
- Linux, Windows
- Play in browser
- No
- Mobile
- No
Project health
- Development status
- Not tracked
- Last updated
- Not tracked
- Stars
- Not tracked
- Contributors
- Not tracked
- License
- Not tracked
- Engine
- Not tracked
Compatibility
- Requires original assets
- —
| Title | UnderworldExporter | UnderworldGodot | Underworld Adventures | The System Shock Hack Project |
|---|---|---|---|---|
| Status | Playable | Unplayable | Semi-playable | Semi-playable |
| Platforms | Windows | Windows | Windows | Linux, Windows |
| Play in browser | No | No | No | |
| Mobile | No | No | No | No |
| Project health | ||||
| Development status | Archived | Active | Active | Not tracked |
| Last updated | 3y ago | today | 2mo ago | Not tracked |
| Stars | 340 | 323 | 74 | Not tracked |
| Contributors | 2 | 5 | 3 | Not tracked |
| License | MIT | MIT | GPL-2.0 | Not tracked |
| Engine | Godot | Godot | SDL2 | Not tracked |
| Compatibility | ||||
| Requires original assets | YesThe project requires original game files from Ultima Underworld 1 and/or 2 to function. | YesRequires game files from Ultima Underworld 1 or 2; GOG versions must be extracted from the game.gog file. | YesThe project recreates Ultima Underworld 1 using the original game files. | — |
| Preview | ![]() | ![]() | ![]() |
Known limitations
- graphics: Limited range of resolutions due to using original game art; 3D models have placeholder texturing.
- gameplay: UW2 is very buggy and not as feature complete as UW1; occasional glitches may occur when loading save games.
- audio: Sound design is very basic; sound effects are from Underworld 2 rather than the original versions.
- animation: No weapon animations in UW0; animations in UW2 are misaligned.
- completeness: Project is in pre-alpha; no support is provided and usage is at your own risk.
- completeness: Not all features of the original game have been implemented; see the Features.md document for detailed status.
Frequently asked questions
Are the Ultima Underworld II: Labyrinth of Worlds clones on this page open source?
Yes — every clone catalogued here is an open-source project. Availability, license, and development-status details for each one are listed in the comparison table above.
What license do these Ultima Underworld II: Labyrinth of Worlds clones use?
UnderworldExporter and UnderworldGodot (MIT); Underworld Adventures (GPL-2.0).
Do I need to own the original Ultima Underworld II: Labyrinth of Worlds to play these clones?
UnderworldExporter, UnderworldGodot, and Underworld Adventures require original game assets to play.
Can I play any of these Ultima Underworld II: Labyrinth of Worlds clones directly in a browser?
Yes — Underworld Adventures has a browser-playable build linked in the comparison table above, no install required.
Which Ultima Underworld II: Labyrinth of Worlds clone is the most actively maintained?
UnderworldGodot and Underworld Adventures are currently under active development, based on recent commit activity. See the "Development status" row above for every clone's current status.
See the full write-up for each clone, or go back to Ultima Underworld II: Labyrinth of Worlds.