cvennevik/slay-the-spire-solver

Slay the Spire solver in the making

Slay the Spire Solver

A WIP tool for finding the best possible actions in Slay the Spire fights.

Table of contents

• About the project
  • Is this open source?
  • Why?
  • How?
• Key concepts to understanding the code

About the project

Is this open source?

Yes! The source code is licensed under the MIT license. You're free to fork the repository and use it as you like.

Do note that this is a personal hobby project, and I will not be accepting any pull requests. It's not that kind of open source. :)

Why?

This is one of those "side projects" I've been told programmers do for fun.

A list of reasons:

1. I've played Slay the Spire a few hundred hours and it's very familiar to me.
2. "Solving" the game sounds like a fun challenge which I can break into smaller goals.
3. I want to try out programming techniques freely!

How?

Two parts:

1. A rules engine for Slay the Spire fights.
2. An AI using the rules engine to find the best actions.

I'll start with setting up the rules engine to handle a single fight: A fresh Ironclad start vs. a Jaw Worm. I'll then write the AI to look for optimal actions, and expand the project there.

I do not have much experience with AI and I have zero experience with machine learning. My first idea is to explore every possible action and game state fully and pick the actions with the highest expected player health at the end of the fight. That is a very naive performance metric, and I'm 99% certain that exploring all possibilities is infeasible. Figuring it out will be part of the project!

Oh, and I will be spending an indulgent amount of time making the rules engine nice and expressive. Optimizing for performance comes later.

Key concepts to understanding the code

• All data structures are immutable.
• GameStates represent every variable known to the player at a single moment in a fight: health, armor, energy, buffs, cards, enemies, etc. Every GameState has a set of Actions a player can take.
• Actions are anything the player can choose to do in a specific GameState: playing a card, using a potion, ending the turn, etc. Every Action is tied to a specific GameState, and resolves to the set of possible GameStates where its effects have been applied. Actions resolve to multiple possible GameStates because the effects of an Action may be random (like drawing cards).
• How legal actions and effects are computed internally is a bit up in the air right now and will probably change drastically.