Primal Gambit

Primal Gambit — Rule of Three

A fan-made revival of EarthCore, built with love, stubbornness, and a lot of AI assistance. Cherry on top, it is free and open source.

What is Primal Gambit ?

If you ever played EarthCore: Shattered Elements, you know the feeling. A card game that was deep, elegant, and just different enough to get under your skin. Then one day it was gone — servers down, no warning, no farewell. Just gone.

I spent hundreds of hours on that game. And I missed it.

So I decided to rebuild it. Not as a professional developer — I'm not one. As someone who wanted to play it again, and figured maybe other people did too. Old fans who remember it, and younger players who never got the chance.

This is Primal Gambit: Rule of Three. It's not a perfect replica. It's a fan interpretation — same core rules, same three-lane structure, same elemental triangle (Fire beats Water, Water beats Earth, Earth beats Fire, Dust loses to everything but has the lowest Risk). But rebuilt from scratch in a single HTML file, with new art generated by AI, a tutorial, statistics, a roguelike mode, and enough content to be its own thing.

If you were an EarthCore player: hello, I hope this brings back some good memories.

Game Modes

 - Tutorial — 8 guided puzzles that introduce the rules one mechanic at a time, with speech bubbles from the cards themselves

- Random Battle — quick single match against an AI opponent, with 5 difficulty levels (Very Easy → Very Hard)

 - Roguelike — a campaign of 20 consecutive fights. You start with a basic deck, earn 2 new cards after each win, and have 3 lives. Lose 3 fights and the run ends

 Cards & Skills

- 49 unique cards currently playable, across 4 elements: Fire 🔥, Water 💧, Earth 🌿, Dust ◈

- The core mechanic: Three lanes, 1v1 card in each lane. Fire beats Water, Water beats Earth, Earth beats Fire. Dust loses to everything. As simple as it is.

- 30+ skills, ranging from passive effects (Vendetta, Seal, Backstab) to manual abilities (Strike, Overgrowth, Vampire Kiss, Disguise Ally) to instants that trigger on placement. Expact short tactical rounds. And the enemy AI is not dumb.

Statistics

- Persistent stats across all sessions (stored in browser localStorage)

- Tracks wins/losses/ties, damage dealt and received, skills used, card performance, deck composition, and records (max damage in a single lane or round, closest win, etc.)

- Per-mode breakdown (each difficulty level, roguelike runs, tutorial puzzles)

- Time tracking — combat time, deck builder time, hub time

Other

- Portrait and landscape layout support, works from phone to HD screen and tablets

- Mulligan system before each fight

- Detailed rules panel with card compendium

- Debug tools for development

About EarthCore 

EarthCore: Shattered Elements was a mobile card game developed by Tequila Games, released around 2014. It featured a unique three-lane battle system, elemental rock-paper-scissors mechanics, and a risk-accumulation system that rewarded patience and misdirection. It was shut down without notice. This project is a fan work, not affiliated with or endorsed by Tabletime. No original assets are used. This is purely a labor of love and is non-commercial.

How Primal Gambit was built (and Credits)

This is the AI disclaimer. I don't think it is AI slop, but you be the judge of that.

I'm not a developer, and I have been building this game in my spare time. I have no training in web development, and I couldn't do decent graphics to save my life. The entire project was built through a conversation — literally. I described what I wanted, and **Claude Sonnet** (Anthropic's AI) wrote the code. Thousands of lines of JavaScript, CSS, and HTML, written iteratively over months of back-and-forth.

It's been humbling, often frustrating, occasionally magical. Wrangling AI tools to build something this complex is its own kind of challenge — you learn to describe things precisely, to debug by description, to hold an entire system in your head while asking a model to change one small piece of it. It doesn't always work. But when it does, it's very satisfying.

Card art was generated in a similar way with **ChatGPT / DALL-E**.

All sound FX are from the amazing resource site [FreeSound.org](https://freesound.org/). The full credits list is in the repository.

All musics are from [Pixabay.com](https://pixabay.com/). Credits go to [Desifreemusic](https://pixabay.com/users/desifreemusic-28163210/), [Akoliks_aj](https://pixabay.com/users/ikoliks_aj-48415707/) and [Nastelbom](https://pixabay.com/users/nastelbom-48128234/).

How to play

1/ Online on itch.io or github (play here). Just open the link in your browser. On iOS and iPadOS: you map tap the Share button, and choose "Add to Home Screen" (still online but in full screen like an app). On chrome or edge, you can install it as a web app for more convenience.

2/  Local installation. Download the ZIP from itch.io or from the github repository (use the green button Code → **Download ZIP**, unzip it, and open `index.html` in your browser. 

Status

This is an active personal project. Cards are added progressively — there are currently ~30 more cards theorycrafted and balanced with an AI-driven game simulator. Skills range from straightforward to mechanically complex. I will implement more cards based on your feedback.

Bugs exist. The AI doesn't always make the right call. Some features are rougher than others. But it's very playable, it's fun, the enemy AI can kick my ass, and it's getting better.

Changelog 

v0.40  (August 2026)

- Added preload of card graphics for slow internet connections

- Added favicon and manifest for local for a cleaner Web App installation

 v0.39 (August 2026)

- Added localization in French, German, Spanish, Italian, Chinese, Japanese (AI made, feedback is welcome)

- Added prologue (short animated comics)

- Added hint micro-button

- Reworked difficulty levels for random and roguelike modes

- Reworked tutorials for clarity

Want to contribute ?

- Motivation : Drop me a message or comment. Tell me what you like or don't like. Tell me your story. Just knowing other folks may enjoy this personnal project would be quite nice.

- Promotion : This game is a tiny island lost in a massive ocean of professional and amateur games with advertisement budgets and/or excellent marketing folks. I don't do social networks, and I have zero interest in self-promotion. If you think this free game deserves some advertisement, this area is by far what would help me most : let your friends and gaming circle Primal Gambit exists, maybe share a screenshot and link. Whatever you think is good. As I said, I am not good at that.

- Bugs & suggestions  : This is a small project so your feedback is most welcome (report bugs, suggest new cards and features). Open a github issue if needed.

- May be a small tip ? : This is a free game. You don't have to donate and I have not set up a donation link yet. That said, if you enjoyed it and if you think it is worth a small tip, let me know. Your donation would help recoup the (small) dev costs. More importantly, it would be an excellent incentive to keep developing new features and cards.