Modding Dune Legacy — Maps, Graphics, PAK Files

Contents

Custom Maps
Graphics & PAK Files
Custom Graphics Modding
Unit & Building Stats
What's NOT Moddable Yet
Contributing

Custom Maps

The easiest way to mod Dune Legacy. Drop an .ini file into data/maps/singleplayer/ or data/maps/multiplayer/ and it appears in the map selection list. No rebuild required.

Map File Format

Maps are plain-text .ini files with the following sections:

[BASIC]
Author=Your Name
Name=Your Map Name
Size=64
NumPlayers=2
MapScale=0

[BRIEFING]
1=First player briefing text
2=Second player briefing text

[Player1]
Credits=5000
Quota=0

[CHOAM]
Carryall=2
Harvester=4
Launcher=5
MCV=2
'Thopter=3
Quad=5
Siege Tank=6
Tank=6
Trike=5

[STRUCTURES]
ID001=Player1,Const Yard,256,100
ID002=Player1,Windtrap,256,103

[MAP]
001=%%%%%%%---~~~~~~~~...
002=%%%%%%--~~~~~~~~...

Terrain Tile Characters

Character	Terrain
`%`	Solid rock — buildings and base structures go here
`-`	Dune sand — impassable to most ground units
`~`	Spice field
`+`	Bloom (bonus spice yield on harvest)
`O`	Player spawn / base start location
`^`	Mountain — impassable to all units
`_`	Water / lake

Map Sizes

Size	Best for
32×32	Tiny skirmish, very fast games
64×64	Standard multiplayer and campaign missions
128×128	Large battles with room to manoeuvre
192×192 / 256×256	Epic scale — long campaigns or city-sim style layouts

Tip: The bundled 2P - 192x192 - SimCity.ini map is a good starting template for large maps. Open it in any text editor to see how the sections fit together.

Graphics & PAK Files

Dune Legacy loads art from .PAK archives under the data/ directory. These are the original Dune II data files (or HD replacements). You can replace or extend them to change how the game looks.

PAK File	Contents
`ATRE.PAK`	Atreides-specific unit and building graphics
`HARK.PAK`	Harkonnen-specific unit and building graphics
`ORDOS.PAK`	Ordos-specific unit and building graphics
`DUNE.PAK`	Shared terrain, UI, and common sprites
`GFXHD.PAK`	HD upscaled graphics (overrides standard PAKs when present)
`SCENARIO.PAK`	Campaign mission data and cutscene assets

Dune Legacy supports loading alternative PAK files. Place replacement PAKs in the data/ directory and they will override the originals at startup. HD texture packs work the same way — GFXHD.PAK is loaded last and takes priority over lower-resolution assets.

Custom Graphics Modding

To replace sprites and textures you need to unpack the relevant PAK file, edit the art assets, and repack. Here's the general process:

Palette Considerations

Dune II graphics use an indexed 256-colour palette. When editing sprites, you must work within the original palette or house-specific palette entries — free colour painting will produce unexpected results at runtime. Many sprite editors (PCED, Grafx2) and general tools like GIMP support indexed-mode editing with a loaded palette.

The palette file is typically IBM.PAL inside DUNE.PAK. Each house also remaps a range of colour indices to its house colours (blue for Atreides, red for Harkonnen, green for Ordos) — keep this in mind when editing unit sprites shared across houses.

PAK Packing Tools

Several community tools exist for working with Dune II PAK files:

DunePAK — command-line tool for extracting and repacking .PAK archives
Dune Legacy's own PAK reader — the source (src/FileClasses/) shows the PAK format if you want to write your own tooling
OpenDUNE tools — the OpenDUNE project ships utilities compatible with Dune II asset formats

The HD texture pack path (GFXHD.PAK) is the cleanest way to distribute a graphics mod — users drop it into data/ and it takes priority without replacing the originals.

Unit & Building Stats

Cost, health, build time, weapon damage, firing rate, and movement speed are defined in the C++ source under src/. Changing these values requires editing source and rebuilding. See BUILD.md in the repository for compilation instructions.

Unit stats — unit type definitions, cost, speed, weapon tables
Building stats — structure type definitions, power consumption, build prerequisites
AI behaviour — computer player attack timing, unit composition, and base-build priorities
Mission scripting — campaign event triggers and win/loss conditions in SCENARIO.PAK

There is no data-driven config file for these values today — they live directly in C++ constants and would need a significant refactor to expose as moddable data without a rebuild.

What's NOT Moddable Yet

Custom Houses / Factions

Dune Legacy ships with three playable houses — Atreides, Harkonnen, and Ordos — plus campaign-only houses (Sardaukar, Mercenary, and Fremen). There is no modding interface to add a new house or swap one out. The house system is embedded in the Dune II engine's mission data, AI, and UI.

Adding a custom house would require forking the source, adding a new HouseType enum value, creating PAK entries with sprites and sounds, wiring it into AI decision trees and mission scripting, and providing house-specific briefing text, mentat portraits, and voice lines. It's a substantial engineering effort.

General Mod Loader

There is no general-purpose mod loader, mod directory scan, or mod conflict resolution system. Mods today are limited to custom maps (drop-in .ini files) and PAK replacements (drop-in asset files). Any logic change requires a source-level patch and a rebuilt binary.

Sound & Music Replacement

The audio assets (voice clips, sound effects) come from the original Dune II data files or replacements placed in data/. Music replacement follows the same PAK drop-in pattern, but full audio mod tooling is not documented and may require source-level changes for some formats.

Contributing

Made a custom map, improved a sprite, or written a useful patch? Contributions are welcome:

Maps — submit via pull request to data/maps/ in the dunecity repository
Bug reports & feature requests — open a GitHub issue
Source patches — see BUILD.md and ARCHITECTURE.md for codebase layout and build instructions
Graphics mods — share work-in-progress on Discord for feedback before submitting a PR