About this tile
Gem Mines is a compact, touch-first gem-engine board game inspired by open-market drafting games. Players collect visible gem tokens, reserve development claims, and buy cards that permanently reduce future costs. The first miner to reach 10 prestige wins.
The market is rendered as a small animated Three.js tabletop: gem tokens sit closest to the player, development cards float in three tidy rows, and each tap is mirrored by synced-store state so the game can be played inside a Poe app instance. The interface is designed for narrow mobile frames around 300x500 while still fitting desktop feed previews.
Rules
Players alternate turns. On a turn, tap a gem token to take it, or tap a development card. If you can afford the card, you buy it, spend matching gems, gain its permanent gem discount, and score its prestige. If you cannot afford it, the card is reserved to your bench and you take a wild gold gem when one is available. Reserved cards can be bought from the reserve tray when affordable.
Permanent discounts make later cards cheaper. Gold gems can pay any remaining cost. The first player to 10 prestige ends the race immediately.
Implementation
Gem Mines uses Poe synced-store for persistent game state, shared mutators for optimistic and authoritative updates, and Three.js for the interactive market. Tests cover deterministic rules, DOM rendering in Happy DOM, mobile viewport fit, Playwright primary flow, and screenshot regeneration.