Play Slay the Spire 2 characters with Slay the Spire 1 card pools, relic pools, and boss content. Classic Cards, Classic Relics, and Classic Bosses can be toggled independently on the character-select screen.

中文说明请见 README.zh-CN.md

To build this mod you need:

1. Slay the Spire 2 — the game DLLs this mod compiles against live in <STS2 install>\data_sts2_windows_x86_64\.
2. .NET 9 SDK — dotnet --version should report 9.x.
3. Python 3.9+ with Pillow installed (pip install pillow).
4. Godot 4.5+ (Mono build) — only required if you want the mod to run on Android. On desktop the build script will skip the Godot import step gracefully if the editor isn't found.
5. An unpacked copy of Slay the Spire 1's assets. See next section.

ClassicMode reuses STS1 card portraits, relic icons, and English/Chinese localization. It does not ship any STS1 assets in this repo — you must bring your own unpacked STS1 directory.

You can produce one yourself from a legitimate copy of STS1:

1. Grab a JAR-unpacking tool (e.g. jd-cli) or simply unzip SlayTheSpire.jar from your Steam install.
2. Extract the contents so you end up with a directory tree that looks roughly like:

   SlayTheSpire_unpacked/
     images/
       1024Portraits/red/attack/*.png
       1024Portraits/green/...
       1024Portraits/blue/...
       relics/*.png
     localization/
       eng/cards.json
       eng/relics.json
       zhs/cards.json
       zhs/relics.json
   

3. Point the build at it via -Sts1Dir or the STS1_UNPACKED_DIR environment variable (see below).

Without this directory the build will fail fast with instructions. If you only want to iterate on C# code you can run with -SkipAssets and reuse a previously-built _pck_src.

From the repo root, in PowerShell:

# Option A: environment variables (recommended for repeat builds)
$env:STS2_GAME_DIR     = "C:\Program Files (x86)\Steam\steamapps\common\Slay the Spire 2"
$env:STS1_UNPACKED_DIR = "C:\path\to\SlayTheSpire_unpacked"
.\build.ps1

# Option B: command-line parameters
.\build.ps1 `
  -GameDir "C:\Program Files (x86)\Steam\steamapps\common\Slay the Spire 2" `
  -Sts1Dir "C:\path\to\SlayTheSpire_unpacked"

# Option C: skip asset prep (C#-only iteration)
.\build.ps1 -SkipAssets

build.ps1 tries to auto-detect a few common Steam install paths, so on a typical setup the first run may "just work" with only -Sts1Dir specified.

A successful build drops everything under build/:

build/
  ClassicMode/
    ClassicMode.dll
    ClassicMode.json        # 0.99+ manifest
    ClassicMode.pck         # packed assets
  ClassicMode-STS2_0.98.x-<version>.zip
  ClassicMode-STS2_0.99-<version>.zip

Install by dropping the whole ClassicMode/ folder into the game's mods/ directory, or by distributing one of the zips.

ClassicMode/
├── Base/                 # Base card/relic classes
├── Cards/                # Ironclad / Silent / Defect card definitions
├── Patches/              # Harmony patches
├── Pools/                # Card / relic pool definitions
├── Powers/               # Classic power models
├── Relics/               # Classic relic definitions
├── assets/               # Localization + manually-shipped images
├── scripts/              # Shared build helpers (see below)
│   ├── mod_build_common.ps1
│   ├── pack_godot_pck.py
│   └── import_assets.py
├── ClassicBootstrap.cs   # Mod entry point + Harmony bootstrapper
├── ClassicConfig.cs      # Persisted user toggles
├── ClassicMode.csproj    # Project file (reads STS2_GAME_DIR)
├── prepare_assets.py     # Turns STS1 unpacked assets into _pck_src content
├── build.ps1             # Standalone build entry point
├── mod_manifest.json
├── LICENSE               # MIT
└── README.md

scripts/ contains the PowerShell / Python helpers the build needs to turn raw source into a packed .pck:

• mod_build_common.ps1 — reusable PowerShell functions: locating Godot, running headless texture import, packing the PCK, and zipping release archives.
• pack_godot_pck.py — minimal pure-Python Godot 4 PCK packer.
• import_assets.py — runs after Godot's headless import to relocate .ctex files out of .godot/imported/ (so the packed PCK doesn't collide with the host game's own .godot/).

None of these scripts depend on anything outside this repository — they are self-contained copies that can be edited in place.

MIT.

ClassicMode ships no assets from either Slay the Spire game; it only references STS2 DLLs at build time and pulls STS1 assets from the user's local unpacked copy at asset-prep time.