Daedalus is open source. What you make with it is not. Every map, texture, scenario and total conversion you build in Daedalus belongs to you — free to keep, to share, and — if it is wholly your own — to sell. Here is exactly how that works, and why.
Daedalus is GPL-3.0 because it is built on the GPL Aleph One engine. That license governs Daedalus's own code — not the files you author with it.
Making a level in Daedalus no more makes it open source than writing a novel in a GPL text editor makes the novel GPL. Same principle as Blender, GIMP and GCC: the tool is free; what you make is yours.
The graybox textures, shapes and sounds Daedalus ships are public domain (CC0). Anything you build on top of them stays completely clean — including for a commercial release.
It comes down to how much of Bungie’s Marathon your work contains — its art and story, or just its name. Nothing about Daedalus changes the answer. Here is the whole map.
A map or scenario that uses Bungie's Marathon — its art, sounds, story, or characters.
Perfect for fan projects. Your original additions are yours, but the work as a whole builds on Bungie's copyright, so it stays in the free, fan-content world.
All-original assets, but set in — or named after — the Marathon universe.
You own the copyright in your art. But “Marathon,” its factions and its story are Bungie trademarks — and a trademark blocks a commercial release even when every asset is your own.
100% your own: geometry, art, sounds, story and name. No Bungie content, no Marathon branding.
This is entirely your work — it just runs on the Aleph One engine. You own it and may license it however you like, commercially included. Ship the engine with it and you simply pass along the engine's source under the GPL; your content stays yours.
A total conversion with none of Bungie’s IP is your own copyrighted work — a commercial game, entirely yours, on a free engine. The same model many commercial titles use on GPL engines. Four things keep it clean:
01
No trilogy textures, shapes, sounds, maps or terminal text. Build on the CC0 grayboxes or your own original assets only.
02
No “Marathon,” no character or faction names, no story, no logo. Give it an original name and universe. This is trademark — separate from, and stricter than, the copyright question.
03
If you distribute the Aleph One engine (or your changes to it) alongside your game, you provide that engine's source under the GPL. Your content — art, levels, story — stays a separate work under your own terms.
04
Clearances, trademarks and any contractor or asset licenses are worth a lawyer's eye before money changes hands. This page is a plain-language guide, not legal advice.
| What | Status | The detail |
|---|---|---|
| The engine source code | Open source (GPL) | Bungie released Marathon 2 in 2000 (GPLv2) and Marathon Infinity in 2011 (GPLv3). This is what Aleph One — and Daedalus — are built on. |
| The game content (the trilogy) | Free, non-commercial | Bungie freed the trilogy to download and play for free in 2005, and licensed Aleph One to distribute it. You may share it, not sell it — it is still Bungie's. |
| The Marathon brand | Owned & active | “Marathon,” its story and its characters are Bungie trademarks — now with a brand-new game. Original work must steer clear of the brand to go commercial. |
Daedalus never bundles or redistributes Marathon game data. You point it at your own free copy from the Aleph One distribution — the same way every other tool has always worked.
This page is a plain-language guide to how these licenses work — not legal advice. Before you sell anything, talk to a lawyer.