Slay the Spire II Setup

This guide covers installing the mod, preparing a player YAML, generating a multiworld and connecting to it. Check the release notes for the game versions supported by the release you are installing.

We recommend the beta branch, where Terairk mainly develops and tests the mod. The main branch remains supported, but receives little, if any, gameplay testing; compatibility is assessed primarily through compile-time checks and player bug reports. Beta branch updates can temporarily break compatibility until the mod is updated.

Install the mod

You need Slay the Spire II and RitsuLib (version 0.6.0 or newer). Install only one copy of the Archipelago mod: either Steam Workshop or a manual installation.

Steam Workshop

1. If you previously installed manually, move mods/Archipelago outside the game's mods directory or remove that copy.
2. Subscribe to RitsuLib and Slay the Spire II Archipelago.
3. Wait for Steam to finish downloading both mods, then start the game.

Manual installation

1. Unsubscribe from the Archipelago Workshop item if you were using it. Keep RitsuLib installed separately.
2. Download Archipelago.zip from the release you want to play.
3. In Steam, open Slay the Spire 2's Browse Local Files action.
4. Create mods/Archipelago inside that game directory and extract the ZIP's contents into it. This works with Windows and Linux archive tools.
5. Confirm that Archipelago.dll, Archipelago.json, the PCK and the lib/ and data/ directories are directly inside mods/Archipelago, without an extra nested Archipelago folder. Keep all packaged dependencies and both game variants together: the root DLL is the loader.
6. Start the game.

The loader selects the build for your installed game version. Later patches on a supported major/minor line can use its newest earlier build, with a log warning. An earlier patch or a new major/minor line needs a matching mod release. Consult that release's notes rather than assuming a newer game update is supported.

Prepare your player YAML

The easiest and recommended way to make your YAML is the YAML Builder on the Slay the Spire II Archipelago website. It walks through every option and downloads a finished YAML. The mod's Mod Website & YAML Builder main-menu button opens the same website.

Alternatively, download Spire2-template.yaml from the same release and edit it by hand, or use the Archipelago Launcher's Options Creator. Set name to the Archipelago slot name you want to use and review the options before generation.

Each participant supplies one YAML. For custom characters, everyone who needs those characters must install the corresponding character mods; test their compatibility before a full multiworld.

If a slot's character mod is missing or broken, you can still connect after a warning. Every character's checks and victories then also count for each missing character. Defect is always playable in that case: it uses its own items if your YAML includes Defect, and otherwise the first missing character's items. Checkpoints saved with a different set of mods may not load; start a new run if one fails. As a last resort, the dev console command ap_release_missing <character> confirm sends all of a missing character's remaining checks; it is disabled in race rooms.

Generate a multiworld

You must generate using Archipelago Launcher v0.6.7 or newer. This requirement applies to the Launcher used for generation; the Launcher is not required merely to play the StS2 mod and connect to an existing session.

1. Install Archipelago Launcher v0.6.7 or newer.
2. Download the .apworld asset from the same mod release. Depending on the release, it is named spire2.apworld or spire2-<version>.apworld.
3. Open the Launcher, select Install APWorld, and choose that file. On Windows, double-clicking the file also works if the Launcher installed its file association. The mod's main-menu Install APWorld action is another way to use the bundled file.
4. Use Browse Files in the Launcher, open Players, and put the participants' YAML files there.
5. Select Generate. The resulting multiworld ZIP is written to output.

Install a newer APWorld before generating a new multiworld when updating it; installing the file alone does not change a seed that was already generated.

To play online, upload the generated ZIP at Archipelago and create a room, or use your preferred Archipelago server. Keep the room's server address, port and any password for connecting.

Connect and play

1. Start Slay the Spire II with the Archipelago mod and RitsuLib enabled.
2. Select Connect to Archipelago on the main menu.
3. Enter the session's server address/port, your YAML's slot name and any password.
4. Connect, then follow the mod's character/run selection.

Avoid unrelated gameplay mods when troubleshooting. All players sharing an in-game multiplayer lobby should use the same Archipelago mod version.

Troubleshooting

• The game loads the wrong mod copy: check both Workshop subscriptions and mods/Archipelago; keep only the installation you intend to use.
• The loader rejects the game version: check the supported main branch and beta branch versions in your mod release's notes and select the corresponding game branch.
• Generation does not recognize Slay the Spire II: install the release's APWorld in the Launcher you are actually using, verify it is v0.6.7+, and retry.
• Connection reports a version mismatch: check that generation used the APWorld supplied with the mod release. A compatibility warning needs investigation; changing the installed APWorld will not rewrite an existing session.