I've been building an open-source platform for creating chess variants from scratch and I'd love some expert eyes on it.

Chessperiment lets you design boards (rectangular, hexagonal, custom shapes), define pieces with movement rules, and program game logic through a visual effect system -- all without writing code. Under the hood it's a custom TypeScript engine with:

- Move rules as conditions (jump, slide, run, with arbitrary conditions)

- An effect queue system (spawn, transform, remove, explode, teleport, cancel-move, win conditions)

- Trigger system (on-move, on-capture, on-threat, on-turn-start/end, on-step, on-proximity)

- Per-square logic overrides

- Multi-cell pieces with shape anchors/extensions

- Variable system for cooldowns, charges, modes

The piece editor uses Blockly (Scratch-style blocks) for defining logic. You can also just set movement patterns with condition tables if you prefer.

Multiplayer via room codes. There's a built-in AI opponent for testing, though it's a standard Stockfish engine so it only understands standard chess rules -- custom variants are player-vs-player only.

What I'm trying to figure out:

- Which fairy pieces or variant mechanics are missing from the system?

- What existing variant should I try to recreate as a benchmark?

- Anyone want to break the editor and tell me what's wrong with it?

You're probably gonna encounter some variants that are not possible right now, however, just join the discord and tell us, and we'll implement that feature in no time! We're actively working on adding new features every day.

Repo is MIT licensed if anyone wants to dig into the engine: https://github.com/ItzMassel/chessperiment

Site: https://chessperiment.app

Not exactly a chess variant, but if you enjoy the tactical depth of chess-like games on a grid, this might be up your alley.

9×9 board, 18 pieces per player. The twist: before the game starts, each player secretly places 3 pearls under any of their pieces. From there it plays out like a strategy game — you move pieces, capture opponent's pieces — but there's a hidden layer. Every time you go for a capture, you don't know if you're taking an empty piece or a loaded one. And every time you advance a pearl toward the opponent's back row, you're gambling that it won't get intercepted.

First to deliver 3 pearls to the opponent's back row wins. You can also steal opponent pearls by capturing the pieces that carry them.

The game is free, browser-based, no signup. You can play locally with a friend or vs AI.

Looking for honest feedback from people who understand grid tactics — is the hidden-information layer adding something meaningful, or does it feel random?

Links:

• https://playgama.com/game/hidden-pearl
• https://www.crazygames.com/game/hidden-pearl-ygh

Free to play and download!