Shipping a mod as a regulation.bin

A modded regulation.bin is safe to load through the engine and risks a ban only when the game's normal Steam launch loads it. See Before you start.

1. Build the modded regulation

GAME="$HOME/.local/share/Steam/steamapps/common/ELDEN RING/Game"
mkdir -p mod
ermod-engine mod bake "$GAME/regulation.bin" mod/regulation.bin level60 class-gear

mod bake does not create the output directory, hence the mkdir. ermod-engine paths prints the game directory if yours differs; on macOS it is inside the Wine bottle.

The game directory is only ever read. Verify that for yourself at any time:

md5sum "$GAME/regulation.bin"   # unchanged before and after

2. Load it

ermod-engine --regulation mod/regulation.bin

The game reads your copy instead of its own, and the game's own regulation.bin is never touched. install.md, step 4 explains how the link works and how to clear it; the rest of install.md sets up the engine if you do not have it yet.

3. Verify in game

Start a new character and check the class screen: every class should show level 60 with a stat spread that keeps its identity, and the extra weapon, shield or catalyst and consumables, the effects of the level60 and class-gear mods applied in step 1.

If nothing changed, read the runtime log. It names the redirect explicitly:

ermod-runtime: regulation redirect — game's regulation.bin -> C:\ermod\regulation.bin

ermod-engine paths prints where the log lives.

Appendix: Mod Engine 2 (legacy)

Mod Engine 2 is archived upstream and is not required by anything here. It is documented only because some players already run it for other mods, and a regulation.bin produced by ermod-engine mod bake is an ordinary file it can load.

Two limitations worth knowing before choosing this route:

• It cannot run .lua mods. It has no runtime inside the game, so it loads only what mod bake wrote into the file: no live params, no hot reload, no overlay, no events.
• We do not test it. The Mod Engine 2 route has never been booted against a current game build here. If it breaks on a game patch, upstream is archived.

If you still want it: unpack a Mod Engine 2 release beside this repo (it is not committed) so you have modengine2_launcher.exe, the modengine2/ directory and config_eldenring.toml, then point its config_eldenring.toml at your mod/ directory:

[extension.mod_loader]
enabled = true
loose_params = false
mods = [
    { enabled = true, name = "elden-ring-mods", path = "/absolute/path/to/elden-ring-mods/mod" },
]

Its launcher is a Windows executable, so it has to run inside the game's own Proton prefix, the same environment plumbing the engine's launcher does for you. That plumbing is the fiddly part, and it is the reason the engine route exists.

Co-op

The engine's co-op syncs Lua mods, not a regulation.bin loaded with --regulation. Every player in a session must load the same file, and nothing checks that for you. See the co-op guide.