Your first passthrough mod (SkyCraft, step by step)

SkyCraft (Minecraft inside Skyrim) is the best first passthrough mod: it has a real download, clear instructions, and it sets up the Minecraft side for you. This guide follows its official README. If anything here disagrees with the README on GitHub, the README wins, because it changes with each release.

1. Check what you have

You need:

Skyrim Special Edition on the Anniversary Edition runtime, version 1.6.x or 1.7.x. It was developed on 1.7.104. Old SE (1.5.97) and Skyrim VR won't work.
A Microsoft account that owns Minecraft: Java Edition. You don't need to install Minecraft yourself: SkyCraft brings its own.
About 3 GB of free RAM on top of what Skyrim uses, about 1.5 GB of disk space, and a graphics card that can run modern Minecraft.

To find your Skyrim version: in Steam, right-click Skyrim → Properties → Installed Files → Browse, then right-click SkyrimSE.exe → Properties → Details → File version.

2. Install a mod manager and SKSE

Skyrim mods load through the Skyrim Script Extender (SKSE64).

Install a mod manager if you don't have one: Mod Organizer 2 or Vortex. They keep mods out of your game folder, so you can undo everything.
Download SKSE64 for your game version from skse.silverlock.org and install it as its page describes.
Install Address Library for SKSE Plugins from Nexus Mods: the All in one (Anniversary Edition) file. Almost every SKSE plugin needs it.
Strongly recommended: Alternate Start - Live Another Life. Skyrim's opening (the cart ride and Helgen) is heavily scripted and can get you stuck with SkyCraft. Alternate Start skips it. Otherwise, use a save from after Helgen.

3. Install SkyCraft

Go to the SkyCraft releases page and download SkyCraft-<version>.zip. Only download it from there: see Staying safe.
Install the zip with your mod manager, like any other mod.

4. First launch

Start Skyrim through SKSE (from your mod manager, or skse64_loader.exe).
The first time, SkyCraft unpacks its Minecraft to %LOCALAPPDATA%\SkyCraft and a small Prism Launcher window asks you to sign in with your Microsoft account. Alt-Tab to it and sign in. This is Microsoft's own login page: SkyCraft never sees your password.
Prism downloads Minecraft, Fabric and Java. This takes a few minutes and only happens once. Skyrim's corner messages tell you when Minecraft is ready.
After that it's automatic: Minecraft starts hidden with Skyrim, opens its own SkyCraft world, and quits when Skyrim closes.

5. Controls you'll need

Minecraft gets most keys. The ones that still go to Skyrim:

Key	Does
G	Skyrim "activate": doors, talking, containers
Esc	Skyrim menu (or closes a Minecraft screen)
J / M	Journal / map
O	Minecraft's pause and options menu
F9	Skyrim quickload

Everything else is Minecraft's: E inventory, F5 camera, T chat.

When it doesn't work

Stuck on "SkyCraft: starting Minecraft…": Alt-Tab and check the Prism window. It may still be downloading, or waiting for you to sign in. SkyCraft tells you after a minute what it's waiting for.
Nothing happens at all: you probably didn't start through SKSE, or your Skyrim version doesn't match. Check SKSE's log in Documents\My Games\Skyrim Special Edition\SKSE.
It crashed or something looks wrong: the log is at Documents\My Games\Skyrim Special Edition\SKSE\SkyCraft.log. For bug reports, set bDiagnostics = 1 in Data\SKSE\Plugins\SkyCraft.ini first.

More fixes in Fixing common problems. Still stuck? Ask in the Help forum with your Skyrim version, SkyCraft version and the log.

Try another one next

Once SkyCraft works, the same ideas apply to its ports. OWCraft (Outer Wilds) and ValCraft (Valheim) both have downloads. Use the Playable with my games filter to see which ones fit your library.