# Evil Engine

> Evil Engine is a passthrough modding engine by Pushbar Interactive, in early development. It mounts the games you already own engine by engine, converts their content into open formats as it loads, and is built to mix them all in one shared multiplayer sandbox. No game's content is ever shipped or extracted. The Steam page is open for wishlists.

## Terms

- **Passthrough modding**: modding through the games you already own, instead of around them. Each player points Evil Engine at their own copy, which it reads in place and converts as it loads, and mods build on the converted result, so nothing is ever extracted, ported or redistributed.
- **Mod modding**: a mounted game's own mods and workshop items mount along with it, each on its own layer a player can switch on or off. Evil Engine's Plugins can build on them like any other content, so the mods themselves get modded.
- **Mount**: one game, on one platform, at one build, read in place from an install folder, a workshop folder or a disc image. Evil Engine runs on its own formats, so a game is only ever something you mount and never something the engine needs to run.
- **Plugin**: Evil Engine's own mod format, built around Lua. A Plugin can require mounts, and every player in a session needs those mounts to join.

## Facts

- Evil Engine learns engines rather than games, so once it knows an engine's formats, every game built on that engine reads through the same code.
- Engine families mounting today: Source, Unity, EA Pegasus, HPL3, Phoenix, BeamNG, Quake, Blitz3D and Unreal Engine.
- Source models, textures and materials already convert into Evil Engine's own open formats.
- Each player's copy is fingerprinted from their own files, so a server can check that everyone's games match without sending any game content.
- Every format can be written by hand or with ordinary tools, and content made without any mount is first-class.
- Evil Engine runs on its own frozen fork of Godot 4.8, and modders only ever work with Evil Engine's API, so nothing they make depends on Godot.
- Maps, multiplayer, Lua Plugins and the shared physics world are planned and not built yet. The devlogs cover what works today.

## Pages

- [Passthrough modding for the games you already own](https://evil-engine.com/index.md): Evil Engine is a passthrough modding engine: mount the games you already own, engine by engine, and mix them in one shared, multiplayer sandbox.
- [Passthrough modding](https://evil-engine.com/passthrough-modding.md): Passthrough modding is modding through the games you already own, and their mods too: mount your own copy in place, convert it as it loads and build on top, with no game content ever extracted or shipped.
- [Devlogs](https://evil-engine.com/devlogs.md): Evil Engine's devlogs: diary entries from the workshop on mounting games, converting their content and building a passthrough modding engine, newest first.
- [Contact](https://evil-engine.com/contact.md): Contact Evil Engine's developer for support, bug reports, suggestions and press, plus answers to common questions about mounting the games you own.

## Devlogs

- [Proving the promises](https://evil-engine.com/devlogs/proving-the-promises.md): Evil Engine's design promises now live in Lean, so a decision that breaks one fails the check. Here's how it's set up, and what it caught. (2026-10-31)
- [Starting over on purpose](https://evil-engine.com/devlogs/starting-over-on-purpose.md): I cleared out the first version of Evil Engine to start again on a handful of rules. Here's what those rules are, and what's been built on top of them since. (2026-10-31)
- [Garry's Mod's materials, matched](https://evil-engine.com/devlogs/every-material-matches.md): Converting Garry's Mod's models, textures and materials into Evil Engine's own formats, and checking the result against what Garry's Mod itself loads. (2026-10-31)
- [Chasing Firefox's pixels](https://evil-engine.com/devlogs/chasing-firefox.md): An experiment: laying out web pages inside Evil Engine, styled with Tailwind classes, and checking every line against what Firefox draws. (2026-10-31)
- [Four games, one mount core](https://evil-engine.com/devlogs/four-games-one-mount-core.md): Garry's Mod, Skate 3 straight off a PS3 disc, Kerbal Space Program and Subnautica all mount through the same core now, with every file readable. (2026-10-30)
- [How far the first version got](https://evil-engine.com/devlogs/how-far-the-first-version-got.md): Before the restart, the first Evil Engine got to 838 commits. It read Garry's Mod's content into Godot and had a sandbox you could actually stand in. Here's what it could do. (2026-10-29)
- [It started as a creature creator](https://evil-engine.com/devlogs/day-one-was-a-crawler.md): Evil Engine's first commit wasn't an engine at all. It was a creature creator for the crawler, with procedural legs and a ragdoll. (2026-10-25)
- [Half-Life 2's models in Godot](https://evil-engine.com/devlogs/half-life-2-models-in-godot.md): sourcegd, a little Godot 4.5 project that reads Half-Life 2's VPKs, lists every model inside them and shows you whichever one you pick. (2025-10-15)

## Feeds

- [Full text](https://evil-engine.com/llms-full.txt): every page above in one Markdown file
- [RSS](https://evil-engine.com/rss.xml): devlogs, newest first
- [Sitemap](https://evil-engine.com/sitemap.xml)

## Optional

- [Steam store page](https://store.steampowered.com/app/3731310/Evil_Engine): wishlist Evil Engine