Show HN: Mulligan Labs – multiplayer Magic: The Gathering in the browser

Mulligan Labs is a browser-based playtester for Magic: The Gathering. No account or install needed. Just create a room, share the link, import a decklist from Archidekt or Moxfield, and play with mouse and keyboard (mobile support is not great right now).

Stack: SvelteKit on Cloudflare Workers, PartyKit (Durable Objects) for the authoritative game server. Clients propose actions over WebSocket; the server validates and broadcasts state.

My background is networking and my cofounder's is industrial design. Neither of us had shipped a codebase like this before. We built it over the last 5 months with heavy Claude assistance. Happy to get into what that actually looked like in the comments.

It's rough in places (the deck builder is just ok right now) but the core multiplayer loop is solid and we have played a ton of games on it with our Commander pod. We'd love feedback, especially from anyone who's played Cockatrice/XMage/Untap and has opinions on what a browser-native version should feel like.