A host screen and player screens synced over WebSockets, showing a question and tallying answers, is a genuinely achievable real-time build — the entertainment counterpart to this register's live-polling idea.
Build it
Effort: a weekendRunning cost: $5–$10/mo
Why CanICodeThis says Build it
A host creating a set of multiple-choice trivia questions is ordinary CRUD
Players joining a game session via a room code, with real-time question sync over WebSockets, is a well-documented real-time pattern
Scoring based on correct answers and speed is straightforward arithmetic
The parts that'll cause problems
Handling many simultaneous players reliably (a real trivia night, not just a few friends) needs real care around connection handling at scale
A polished, animated host-screen presentation (countdown timers, leaderboard animations) is real, separate front-end polish
Anti-cheating measures (preventing players from looking up answers) are genuinely hard to fully solve and mostly rely on time pressure
How I'd build this
frontend
Next.js
hosting
Vercel
MVP scope
Host creates multiple-choice questions
Players join via a room code, questions sync in real time
Score based on correct answers and speed
Postpone to v2
Scaling to large simultaneous audiences
Animated host-screen presentation
Question categories and difficulty levels
What it actually costs to build
AI agent — with a subscription (Claude Pro/Max, Cursor, etc.)
$0 marginal
AI agent — pay-per-use API, no subscription
$43–$86 one-time
Hosting, once it's running
$5–$10/mo
Domain name, if you want your own
~$12/yr
The build prompt
Build me a multiplayer trivia game: a host creates multiple-choice questions, players join via a room code on their phones, questions sync in real time over WebSockets, and scoring is based on correct answers and how fast they were submitted. Built for a small group (friends, a classroom) rather than a large public audience.