Stack or Sink

The problem

Building a fair, physics-heavy multiplayer game where players can't cheat, and shipping it repeatably.

What it does

• Grab, carry, place and climb, with throw, catch and deflect counterplay and ragdoll physics.
• Five hazards (flood, lava, acid, sand, snow) and five match formats, including bot-filled matches and team doubles.
• Onboarding, XP progression, parties, badges, daily objectives and leaderboards.
• Cosmetic-only purchases, with a live kill switch for the shop.

How it's built

• Luau with strict typing, synced from files with Rojo; server services and client controllers kept separate, with tuning in one config.
• Roblox DataStores for versioned player profiles; publishing through the Roblox Open Cloud API.

Engineering decisions

• Never trust the client: the server decides every grab, hit, catch, score and reward.
• A "project brain" of locked rules (mobile-first, no pay-to-win) that every human and AI contributor reads first.
• Reproducible publishing: each release is built from committed code only, tested on that exact file, and the last 10 publishes are hashed for rollback.
• Hundreds of automated tests in Studio, locally and in CI, plus a type-check ratchet that only lets errors go down.
• Honest numbers: a test checks the README's figures against the repo, and a conclusion drawn from a funnel step that never fired was retracted.