Brisca
A roguelike card game with a Spanish deck, 1v1 vs AI, inspired by Balatro. 100% deterministic TypeScript engine with a headless sim harness that runs thousands of runs to balance thresholds and rank talismans.
The Challenge
Traditional Spanish card games rarely go beyond the casual one-off match. Balatro proved roguelike loops can inject variety and math into a familiar deck, but no project had taken that formula to Brisca.
Results
- 100% deterministic engine (mulberry32 PRNG), simulable headlessly
- 30 talismans with a parametric hook system (onTrickResolve, onMatchStart...)
- Sim harness with 10 scenarios: thresholds, combos, fairness, economy
- 3D card rendering with React Three Fiber + react-spring
The Solution
I built a full roguelike with 12 matches per run across 3 taverns with bosses, 30 talismans across 3 rarities, a pre-boss shop and Balatro-style scoring (chips × mult). The engine is pure TypeScript without React, simulable headlessly — that enables a sim harness running thousands of runs to detect dead talismans, broken combos and trivial thresholds.
Motivation
I wanted a project where game design was measurable, not just intuitive. Brisca was ideal because I've known it forever and its rules (40-card deck, fixed lead, trump suit) are simple but enable deep strategic layers.
Challenges
The hardest part was separating the pure engine from the render layer so the same logic could run both in a real match (with React Three Fiber animations + Zustand) and in a 10,000-run sim with no DOM or framework. Plus rebalancing talismans from data — the sim would say 'El Avaro never fires' and I'd have to dig into the hook.
Learnings
I learned that a sim harness is the best game design tool you can have: it turns debatable intuitions ('this talisman is OP') into quantitative facts ('synergy 452 vs baseline 310'). And that the cost of keeping the reducer pure pays itself off the moment you need to test it at scale.
Context
Playable end-to-end: 12 matches, rewards, shop, 3 bosses with traps, 30 talismans with curated traditional art. Meta-progression and final balance pass pending after sim reports.