---
title: "Spellblunder"
url: "https://aigamehub.app/en/games/claude-code-opus-5-5-and-i-made-a-multiplayer-wizard-game-in-c4a835"
source: "https://www.reddit.com/r/ClaudeAI/comments/1xbfe8b/claude_code_opus_55_and_i_made_a_multiplayer"
source_type: "reddit"
play_url: "https://spellblunder.com/"
platform: "desktop"
login_required: false
pricing: "free"
origin: "original"
ai_tools: ["Claude Code", "ElevenLabs"]
game_languages: ["en", "fr"]
author: "Difficult_Ocelot_660"
author_handle: "Difficult_Ocelot_660"
category: "Action"
categories: ["action", "adventure", "casual"]
tags: ["browser-3d", "claude-code", "indie", "multiplayer", "spell-mixing", "wizard"]
added: "2026-10-22T02:24:08.382Z"
updated: "2026-10-21T06:13:05.000Z"
locale: "en"
content_locale: "en"
---

# Spellblunder

Spellblunder is a free 3D wizard game that runs in the browser. Players mix elements into spells and the spells often backfire, in the style of Magicka. It includes a five-chapter campaign, an arena, online co-op and duels, bots, and supports six languages. Desktop only, keyboard and mouse.

## Description

Spellblunder is a free browser-based 3D wizard game where you combine elements into spells that frequently backfire. It offers a five-chapter campaign, an arena, online co-op and duels, and bot opponents. The game supports six languages and is playable on desktop with keyboard and mouse. Claude Code (Opus 5.5) wrote the code, while the developer handled the ideas and playtesting; the author talks to Claude in French and used ElevenLabs to generate and compare sound variants on a listening bench.

## Original post

Claude Code (Opus 5.5) and I made a multiplayer wizard game in 19 days

Spellblunder is a free 3D wizard game that runs in the browser. Think Magicka: you mix elements into spells, and they backfire a lot. I started it on October 2. Claude Code with Opus 5.5 wrote all of the code. My part was the ideas and a lot of playtesting. Some numbers from the repo: - about 1,000 commits in 19 days - 106k lines of TypeScript for the game, 6k for the server, 59k for tests - 2,552 automated tests How it went: - I ran several Claude Code sessions in parallel, each in its own git worktree, and merged them one by one. - For new screens, Claude made three mockups and I picked one. - Online play is lockstep, which only works if every browser computes the exact same game. Claude wrote a determinism bench that replays scripted matches and hashes the result, and we compare that hash between Node and real browsers. - Before launch, a multi-agent workflow hunted bugs: finders, two verifiers per bug, then one fixer per group of files. 92 bugs fixed. - One real prompt, translated from French (I talk to Claude in French): "I'd like to change the sound the character makes when walking in water. Could you generate variants in ElevenLabs and put them on the listening bench?" It generated eight takes, trimmed them, matched their loudness and put them on a test page. I picked one, played with it, still didn't like it, and asked if we could just drop the sound. It added a "Silence" option to the bench, and that's what shipped. What Claude couldn't do for me: tell whether a fight feels fair or a spell feels good. That part was me, mostly on a Chromebook. There's a five-chapter campaign, an arena, co-op and duels online, bots, and six languages. Desktop only, keyboard and mouse. Happy to answer questions about the workflow. https://spellblunder.com   submitted by   /u/Difficult_Ocelot_660   to   r/ClaudeAI [link]   [comments]