Factorio Must Fall

A combat autobattler for Factorio 2.0 (Space Age era; developed against 2.0.76). Build a factory that builds an army that fights for you.

Not affiliated with — but surely name-inspired by — The Factory Must Fall, a standalone game in the same genre that was already on Steam (though not yet released) when this mod was made. Check it out if you want more of this.

What it does

You craft a Vehicle Hangar — a power-hungry assembling machine. Instead of items, it builds hunters: autonomous spidertron-class war machines that drive off on their own, seek out the nearest enemy anywhere nearby, and fight without a driver. Clear a nest and they roll on to the next. Lose one and you just build another.

Each hunter is a recipe combining a vehicle (the chassis — how tough it is) with ammo (the weapon — how hard it hits):

Hunter	Recipe (vehicle + ammo)	Role
Light	car + firearm magazines	cheap, fast, fragile
Medium	tank + piercing magazines	sturdier machine-gunner
Heavy	tank + explosive rockets	rocket bombardment
Cannon	tank + explosive cannon shells	hard-hitting direct fire
Siege	spidertron + uranium cannon shells	armored heavy cannons
Nuclear	spidertron + atomic bombs	walking apocalypse (immune to its own nukes)

Feed the hangar power and ingredients and it churns out a self-deploying army. Tougher vehicles make tankier hunters; stronger ammo makes deadlier ones — so the fleet scales with your factory's tech and output.

Gun counts, per-hunter resistances, and friendly fire are all adjustable in Settings → Mod settings.

Requires flib.

Layout

info.json            Mod manifest: name, version, factorio_version, dependencies.
settings.lua         Settings stage — defines mod settings.
data.lua             Data stage — registers prototypes (requires prototypes/*).
data-updates.lua     Data stage, second pass — modify other mods' prototypes.
control.lua          Runtime stage — events, game logic (uses `storage`, not `global`).
changelog.txt        Strict Factorio changelog format (drives the in-game changelog).
locale/en/locale.cfg Translatable strings (setting names, item names, messages).
prototypes/          Prototype definitions, required from data.lua.
scripts/             Runtime Lua modules, required from control.lua.
graphics/            PNG assets.
dev/link.sh          Symlink this repo into the Factorio mods dir for live dev.
dev/factorio-defs/   Generated Factorio API type defs for LuaLS (gitignored).
package.json         Dev tooling only (FMTK) — not shipped. npm scripts below.

Load stages (in order)

settings → settings-updates → settings-final-fixes → data → data-updates → data-final-fixes → game starts → control.lua.

The data stage builds the global data.raw prototype table. The control stage runs inside a live save and may not touch data.raw — it uses the runtime API.

Develop

npm install          # one-time: pull pinned FMTK tooling
npm run defs         # one-time: generate Factorio API type defs into dev/factorio-defs/
npm run flib         # one-time: extract flib into dev/flib/ for LuaLS autocomplete
./dev/link.sh        # symlink into ~/Library/Application Support/factorio/mods/
npm run check        # fast Lua syntax gate (node-only) — run before loading the game
luacheck .           # deeper lint (needs a Lua toolchain; config in .luacheckrc)

Then start Factorio. Enable the mod in Mods. After Lua edits, restart Factorio (or reload the save) — there is no hot reload for mod code, though the in-game console (/c) helps for quick experiments.

Editor

Open in VS Code and install the recommended extensions (.vscode/extensions.json):

• sumneko.lua (LuaLS) — autocomplete & type-checking, configured by .luarc.json against the generated Factorio API defs.
• justarandomgeek.factoriomod-debug (FMTK) — breakpoint debugger + profiler.

node_modules/ and dev/factorio-defs/ are gitignored; npm install && npm run defs rebuild them. None of this is shipped — the mod is pure Lua.

Release

Releases are automated. Pushing a v* tag triggers .github/workflows/release.yml, which builds the zip and publishes a GitHub Release with it attached (notes come from the matching changelog.txt section).

npm run version      # bump info.json + add a new changelog section
#                      ...then write that section's notes and commit + push
npm run release      # tag v<version> from info.json and push it -> CI publishes

The tag must match the info.json version, and changelog.txt must have a section for it (the release script checks both).

Manual / mod-portal options:

npm run package      # build -> factorio-must-fall_<version>.zip locally
npm run publish      # package + upload to the mod portal (needs an API key)

Packaging is handled by FMTK; what gets included is everything except dotfiles, modname_*.zip, and the globs in info.json#/package/ignore (node_modules, dev/, package.json, CLAUDE.md).

Reference

• Modding docs / tutorial: https://wiki.factorio.com/Modding
• Lua runtime API: https://lua-api.factorio.com/latest/
• Prototype docs: https://lua-api.factorio.com/latest/prototypes.html

License

MIT © Jake Gaylor