Eye of the Beholder II - Compose Multiplatform Remake

This project aims to bring the classic first-person dungeon crawler to modern platforms while staying faithful to the original VGA DOS experience. Built entirely in Kotlin, it runs on Android, iOS, Desktop, and Web.

It started in Flutter, as a way to learn it, and moved to Compose Multiplatform to go faster. Thanks to Claude Code there is now something to actually look at — and to play, in your browser:

eob2.pelotasplus.dev →

Features

• Binary file parsing for original game assets (MAZ, VCN, VMP, PAL, INF, CPS, DEC, DCR, ITEM.DAT)
• LCW and run-length decompression
• 3D viewport rendering with wall depth, decorations, doors, items and monsters
• Level script interpreter (doors, triggers, plates, spawns, set pieces)
• Combat, items, resting, saving and loading
• Full-screen cut scenes, the ending sequence and the credit roll
• AdLib sound rendered ahead of time to samples
• A debug panel: jump to any level and entry point, walk through walls, freeze the monsters, and a viewer for the CPS graphics
• Spells (in progress) — wands, scrolls and the spells the dungeon casts at the party all work; what is missing is the party's own spellbook: memorising at rest, praying, scribing scrolls, and the casting UI that goes with them
• Bugs, bugs, and more bugs. Help me squash them!

Platforms

Platform	Status
Web (Wasm/JS)	Deployed and played — the only one that gets tested
Desktop (JVM)	Built, not play-tested
Android	Built, not play-tested
iOS	Built, not play-tested

Everything is one Kotlin Multiplatform codebase, so all four targets build — but the web build is the one actually played, and it is where any bug will have been found. The other three are expected to work rather than known to.

Quick Start

# Run desktop application
./gradlew :composeApp:run

# Run the web build, rebuilding on save
./gradlew :composeApp:wasmJsBrowserDevelopmentRun --continuous

Tests

Most of the suite reads the game's own data files, which are not in this repository, so there are two ways to run it:

# Everything, for a checkout with the game files beside it
./gradlew :composeApp:jvmTest

# Only what needs no game data - what CI can run
./gradlew :composeApp:jvmTest -PwithoutGameData

Rendering is guarded by golden-image tests: each one draws a known frame with the real assets and compares it byte for byte against a reference PNG in composeApp/src/jvmTest/goldens/.

Letting an agent play

The game can be played by an AI agent through MCP. The agent is told only what a player could know: the squares in sight as they look, the party, the messages, the screen as a picture. It acts by naming what a player does (step, turn, use a hand, cast from the book), and the game stands still between its actions, running only when it says to wait.

# Once, and again after changing it: the server the agent talks to
./gradlew :agentServer:installDist

1. Start Claude Code in this project. .mcp.json registers the server as eob; allow it when asked.
2. Run the game, open the Debug menu and switch Agent on. It calls the server on 127.0.0.1:47110 and reads Agent: connected once it is there.
3. Ask the agent to play.

With the agent switched on, the Debug menu also offers QA mode: the agent is then told everything — the game's own warnings, what has not been written yet, the whole world behind the view — and can set a check up directly (teleport, give a spell or an item, spawn a monster, heal). It is for hunting bugs, and is off unless the person at the game turns it on.

The game only ever connects out, to this machine, and only while the switch is on. Switching it off, or the server going away, gives the game back to the player. The design is in agentServer/ and composeApp/src/commonMain/kotlin/pl/pelotasplus/eyeofbeholder/agent/.

Credits

This project would not have been possible without the people who worked out how Westwood's file formats and engine behave, and then wrote it all down.

• ScummVM — its engines/kyra/ is a reverse-engineered reimplementation of the Eye of the Beholder engines, and it is what made the hard bugs findable. When a wall drew wrong, or a script did something that made no sense, there was somewhere to go and see how it was supposed to behave. Decades of patient work by people who did it for the love of these games, and freely given away; this project would have stalled a dozen times over without it. ScummVM is licensed GPL-2.0-or-later; it is used here as documentation rather than as a source of code.
• The Shikadi ModdingWiki — community documentation of the Westwood Studios file formats, including the LCW/Format80 compression these assets are packed with.
• Eye of the Beholder file formats by JackAsser — notes on the MAZ, VMP, VCN, DEC and INF formats specifically.

And, of course, Westwood Associates and SSI, who made the game in 1991.

Legal

This is a fan project for educational purposes. The game's own data files are not in this repository — you need your own copy of Eye of the Beholder II to run it.

Two things derived from the game are here, and both are here because the tests need them:

• the golden PNGs in composeApp/src/jvmTest/goldens/, which are frames this renderer drew from the original artwork and are compared against to catch rendering regressions;
• short strings from the game's own text — screen messages, and the dialogue of the ending — quoted in the source so that what is drawn can be asserted.

Eye of the Beholder and Advanced Dungeons & Dragons are trademarks of their respective owners; this project is not affiliated with or endorsed by any of them.

License

MIT, covering the code in this repository. The rendered frames and quoted strings described above are derived from the original game and are not ours to license.