Ys I Chronicles — Archipelago Randomizer

An Archipelago multiworld randomizer for Ys I Chronicles+ (Steam PC version). Currently supports Ys I only; Ys II support may be added in the future.

Requirements

• Ys I & II Chronicles+ (Steam, PC version)
• Archipelago 0.6.6+

Setup

Quick install (precompiled)

1. Back up your game's steam_api.dll by renaming it to steam_api_orig.dll
2. Copy from the player/ directory into the same folder as ys1plus.exe:
   • steam_api.dll — proxy that loads the AP client
   • aphook.dll — full AP client
   • ap_connect.txt — edit with your server info
3. Install player/ys_chronicles.apworld into your Archipelago worlds directory
4. Edit player/Ys I Chronicles.yaml to configure options, then generate a seed
5. Launch the game normally

Build from source

# Build everything
tools/build_apworld.sh

# Deploy to game directory
tools/setup_mod.sh [server] [slot] [password]

How It Works

The mod injects aphook.dll into the game via a steam_api.dll proxy. The DLL:

1. Hooks give_item() — intercepts all vanilla item grants (chests, NPCs, bosses, shops)
2. Connects to AP server — WebSocket client sends location checks and receives items
3. Suppresses unauthorized items — only items granted by AP are allowed in inventory
4. Monitors memory flags — detects location checks via flag transitions
5. Syncs on save load — re-applies AP state whenever a save file is loaded

Legal

This project requires a legally purchased copy of Ys I & II Chronicles+. No game code or assets are distributed. All interaction is through runtime memory hooks and the Archipelago protocol.

Ys I & II Chronicles+ is developed by Nihon Falcom and published by XSEED Games.

License

MIT

Links

• Archipelago
• Ys Wiki