STSModSetup

A base structure for the creation of mods for Slay the Spire based off of the wiki from BaseMod's Getting Started Guide

Setting Up Your Development Environment

Install Maven

Maven is used for dependency management and packaging any mods you create. Download it here and install it.

Download the Skeleton Repository

Download this repository as a zip. Unzip where you want to set up your dev environment.

Do not clone or fork unless you really want to go through the hassle of changing git things later

Adding Dependencies

The lib folder is where we will keep our dependencies. This is very useful if you want to have multiple STS modding projects.

Download the latest release .jar for each project and place in the lib folder

• ModTheSpire
• BaseMod

The final dependency you will need is the actual game. There is a file called desktop-1.0.jar located where your game is installed. Copy desktop-1.0.jar into the lib folder.

ModTheSpire and BaseMod only support the main branch of the game (i.e. not the beta branch).

When Slay The Spire updates, you will need to replace desktop-1.0.jar with the latest version.

Import Project Into an IDE

This set up should be IDE agnostic (i.e. you can use whatever IDE you like). Here are steps for importing your project into two of the more popular IDEs

IntelliJ

File -> Project from Existing Sources -> Select ExampleMod folder or your own mod that follows the structure of the ExampleMod -> Select Maven -> Press next until your project is built.

Click on the Maven Projects tab on the right of the editor and click the refresh icon to load your dependencies from the pom.xml into your project. (If no Maven projects tab on the right View -> Tool Windows -> Maven Projects)

Eclipse

File -> Import -> Maven -> Existing Maven Projects -> Browse and select ExampleMod folder or your own mod that follows the structure of the ExampleMod.

You may need to right-click your project Maven -> Update Project -> Select your current project -> Click OK.

Setting up Slay The Spire for Mods

If you have played Slay the Spire with mods or have set up ModTheSpire, you can skip this step. In this tutorial, the directory that Slay the Spire is installed in will be refered to as the Slay the Spire directory.

Follow the section titles Playing Mods on ModTheSpire's Wiki.

Copy BaseMod.jar from your lib folder into your mods folder in your Slay the Spire directory.

Writing Your First Mod

Package the Skelaton App

If you have followed the steps so far, you should be able to package the mod that you downloaded in the skelaton repository.

Open a terminal in the ExampleMod directory and run mvn package. This should package ExampleMod into ExampleMod.jar. You can find it in /_ModTheSpire/mods/ExampleMod.jar.

Copy ExampleMod.jar into the mods folder in your Slay the Spire directory.

You should be able to run Slay the Spire by running MTS.cmd (MTS.sh on a mac).

Write Some Code

You've probably noticed our ExampleMod didn't do anything. Let's change that!

Right now, ModInitializer.java should look like this

@SpireInitializer
public class ModInitializer {


    public ModInitializer(){
        //Use this for when you subscribe to any hooks offered by BaseMod.
        BaseMod.subscribe(this)
    }

    //Used by @SpireInitializer
    public static void initialize(){

        //This creates an instance of our classes and gets our code going after BaseMod and ModTheSpire initialize.
        ModInitializer modInitializer = new ModInitializer();
    }

}

BaseMod uses listeners to run code when certain events happen. Let's implement the PostDrawSubscriber.

public class ModInitializer implements PostDrawSubscriber {

@Override
public void receivePostDraw(AbstractCard card) {
    System.out.println(card.name + " was drawn!");
}

Run mvn package and copy the packaged .jar file into your mods folder and run your game. You should notice the card name being printed out in the ModTheSpire console.

Going Further

What Other Listeners Exist

Most mods will probably be more complicated than printing something when a card is drawn. A full list of listeners can be found in src/main/java/basemod/interfaces in BaseMod.

Looking at the Game's Source Code

What else can I do with AbstractCard? What about AbstractDungeon? How does Slay the Spire work under the hood. A lot of these questions can be answered by looking at the game's source code. You can do this by decompiling the game. Follow this guide to do that.

Can I Make My Own Listener

You bet you can. Check out how listeners are made in BaseMod and check out the documentation about SpirePatch in the ModTheSpire docs

Happy Modding!