Getting started with UE4SS mods for Subnautica 2

Every SN2*Tweaks mod on this site needs the same two things installed first. Here's the once-only setup, and the one gotcha that catches everyone.

The two prerequisites

Subnautica 2 Lua mods run on UE4SS, a script loader for Unreal Engine games. On top of that, SN2ModSettings gives mods an in-game settings UI — it's how the sliders in my mods appear under Settings → Mods.

UE4SS for Subnautica 2 — install so dwmapi.dll sits next to Subnautica2-Win64-Shipping.exe, with the ue4ss/ folder beside it
SN2ModSettings — mods load without it, but you'd have no way to change their defaults short of editing files by hand

Installing a mod

Extract the mod archive so its folder lands inside <game>\Subnautica2\Binaries\Win64\ue4ss\Mods\. The folder contains an enabled.txt and a Scripts\ directory — if you can see those at ue4ss\Mods\<ModName>\, it's in the right place.

The gotcha: mods.txt load order

Open ue4ss\Mods\mods.txt and add a line for the mod, e.g. SN2PowerTweaks : 1. This makes the mod load before SN2ModSettings — otherwise the settings UI won't see it until you restart the game a second time. It's the single most common "the mod isn't working" report, and it's always this.

Check it worked

Launch the game and open Settings → Mods. The mod should be in the list with its sliders. Changes apply to your running save within about a second — no restart needed.