Bad Decisions Inc.

Bad Decisions Inc. Mockups

Inspiration

Every friend group in Vegas asks the same questions: "Where should we eat?" "What should we do next?" Nobody wants to decide, everyone has an opinion, and you burn half the night arguing. Vegas is a city built on settling things with a gamble -- so we thought, why not settle group decisions the same way? Instead of doom-scrolling Yelp or doing the painful "I don't care, you pick" dance, we built a platform where you literally wager your say on fast, chaotic mini-games.

Winner picks the spot. Loser takes the punishment card. Just like Vegas: the house always deals, and somebody always walks away with a story.

What it does

Bad Decisions Inc is a real-time, mobile-first party mini-game platform designed for groups on the go. One person hosts a room and everyone else joins instantly by scanning a QR code -- no app downloads, no sign-ups for players. The host picks from five Vegas-themed mini-games:

Rebel Shake -- a 15-second phone-shaking frenzy (like shaking dice at the craps table) Vegas Pan Flip -- flick your phone to launch and flip an egg (high-stakes flipping) Poker Chip Tap -- spam-tap a 3D poker chip for the highest score before time runs out Kanpai Timing -- tap in rhythm as two beer glasses clink to a beat (precision under pressure) Chopstick Catch -- catch falling sushi with chopsticks in a 3D scene (dexterity challenge)

Every round has a synced countdown, live race-track leaderboard, and real-time scoring. The winner earns the right to call the next move for the group. It's how Vegas would solve your group's indecision.

How we built it

Turborepo monorepo with a Next.js web app and shared backend package
Convex for the real-time backend -- rooms, players, join requests, and live score syncing all happen through Convex mutations/queries with zero polling
Clerk for host authentication (players join as guests via QR code, no auth friction)
React Three Fiber + Three.js for 3D game scenes (beer glasses clinking in Kanpai, poker chip spinning in Tap, chopsticks + falling sushi in Chopstick Catch, pan/egg physics in Flip)

-- Fully mobile-first responsive design with a dark/gold Vegas casino aesthetic

Challenges we ran into

Real-time sync across devices was the hardest problem. Every player needs to see the same countdown and game timer despite network latency and clock drift. We built a custom useSyncedRound hook that anchors everything to server-side timestamps rather than local clocks.

QR code join flow -- making the guest join experience feel instant (scan -> name -> play) while still giving the host approval control over who enters the room.

Accomplishments that we're proud of

Zero-install player experience -- scan a QR code, type your name, and you're in. No app store, no sign-up. This was a deliberate design choice to match the spontaneous energy of a Vegas night out. The race-track leaderboard -- watching avatars slide across the track in real-time as scores update is genuinely fun to spectate, especially on the host's screen projected for the group.

The 3D interactions feel physical -- shaking your phone, flicking to flip, tapping a poker chip, catching sushi with chopsticks. Every game uses the phone as a physical controller, not just a screen.

What we learned

Real-time multiplayer is a fundamentally different paradigm from request/response. Convex's reactive queries made it viable at hackathon speed, but thinking in terms of "what does every client see right now" instead of "what did the server respond" type sh.

Mobile browser APIs (DeviceMotion, touch events, WebGL) are powerful but inconsistent. Testing on real devices early and often saved us from discovering permission and performance issues at demo time. Keeping the join flow frictionless matters more than adding features. Every extra tap between "scan QR" and "playing the game" is a player you lose.

What's next for Bad Decisions Inc.

Punishment cards & reward system -- the winner doesn't just pick the spot; losers draw from a deck of Vegas-style dares and challenges. Think: "Loser has to order in a terrible accent" or "Loser pays for the appetizer."

Vegas venue integration -- tie game outcomes to actual Vegas restaurant/bar recommendations so the winner's choice is surfaced automatically ("You won -- here are 3 spots nearby, pick one"). Tournament mode -- chain multiple mini-games into a best-of series with cumulative scoring, so one night out becomes a full Vegas bracket.

More mini-games -- slot machine reaction time, roulette spin prediction, blackjack-style number games. The Vegas theme is an endless well of game mechanics.

Native mobile app (the Expo app in the monorepo) for push notifications, haptics, and smoother device motion access.

RHYTHM GAMESSSSSSSSSSSSSS.