Inscryption Online

Networked player-versus-player for Inscryption, running inside the real game client.

Everything that existed before this was either local hotseat, a Tabletop Simulator table, or a browser/Godot reimplementation of the card game. This is the actual game, over the network, against another person.

What works

• Steam lobbies and P2P — host, browse, join. No IPs, no port forwarding, no master server. Verified across two machines on two Steam accounts.
• Direct IP / LAN as a fallback for non-Steam copies.
• Standalone versus mode launched from the main menu. No campaign run required, no map node consumed, and saving is disabled for the duration so a match can never touch your save.
• Real turn order with a turn indicator; cards appear on the opponent's board as they are played.
• Authoritative board sync each turn, so sacrifices and combat deaths stay correct.
• Deck builder using the game's own 3D card table, paged, persisted to disk.
• Clean match end on both clients, back to the main menu with the result.

Install

1. Steam → Library → right-click Inscryption → Manage → Browse local files
2. Extract InscryptionMP-install.zip into that folder, next to Inscryption.exe:

   Inscryption.exe
   winhttp.dll
   doorstop_config.ini
   BepInEx/plugins/InscryptionMP.dll
   

3. Launch the game and press F7.

Both players need the same build.

Playing

1. One player clicks Host Lobby, the other clicks Find Games and picks the lobby.
2. Either player clicks START MATCH — both clients enter a match together.
3. The host takes the first turn. Ring the bell to pass.

F7 menu · F8 start match · F12 abort out of anything

Deck building

F7 → DECK → Open Card View. Click a card to add it; View My Deck to remove. Decks are 6–20 cards, stored in BepInEx/config/inscryptionmp-deck.txt.

Each player brings their own deck. Decks are never synchronised — the peer only ever resolves a card name, which the game's own CardLoader already handles.

The card pool ignores campaign progression on purpose: a versus deck shouldn't be gated behind someone's single-player unlocks.

How it works

Each client runs an ordinary single-player battle in which it is the player and the opponent is driven by the network instead of the AI. A card the peer plays into their slot N materialises in our opponent slot N. The engine's own combat resolution runs untouched.

That is the whole trick, and it falls out of Opponent being abstract with a virtual QueueNewCards().

See NOTES.md for the engine details and the bugs that cost real time.

Not done

• Act 2 (GBC.Pixel*) is a parallel class hierarchy and is untouched.
• Some rarer card effects may not replicate perfectly on the opponent's screen. Please report anything that looks wrong.
• Play with people you trust — this is built for playing with friends, not for competitive or ranked play.

Building

tools/deploy.sh          # build + install into every local copy of the game
tools/peer.py            # scripted opponent for testing without a second client

Requires the .NET SDK. BepInEx packages come from https://nuget.bepinex.dev/v3/index.json (see NuGet.config) — they are not on nuget.org.

AI disclosure

Most of this mod's code was written by Claude Opus 5 (Anthropic), working with the author across a single extended session: the author drove the design, tested every build against a second machine, and found a good number of the bugs.

Disclosed per Thunderstore's policy on LLM and AI-generated files (https://wiki.thunderstore.io/llms-and-ai-generated-files). The same disclosure is present in the assembly metadata (AI_Assisted_Creation, AI_Model_Vendor, AI_Model), and every commit in the repository carries a Co-Authored-By trailer.