prototype

Purpose

This is the concept prototype — a fast, throwaway build that answers one question: "Is this core idea actually fun to interact with?"

Default use — run right after /brainstorm and /setup-engine, before writing GDDs or architecture docs. Its verdict determines whether the concept is worth the investment of full design documentation.

Mid-production? You can also run this at any stage to test a specific mechanic, design change, or technical question. Pass --spike to activate spike mode: a lightweight ~4-hour build with no GDD prerequisites and no phase gate implications.

Already have GDDs and architecture complete? To validate the full game loop before committing to Production, run /vertical-slice instead.

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Phase 1: Define the Question

Resolve the review mode (once, store for all gate spawns this run):

1. If --review [full|lean|solo] was passed → use that
2. Else read production/review-mode.txt → use that value
3. Else → default to lean

Check for spike mode: If --spike was passed, skip to the Spike Mode section at the bottom of this skill.

Otherwise, use AskUserQuestion to confirm intent before proceeding:

• Prompt: "How would you like to use this prototype session?"
• Options:
  • Prototype this concept — build a throwaway build to validate the core idea is fun before writing GDDs (1–3 days)
  • Skip — concept already proven — I have enough evidence this works; log it and proceed directly to design
  • Mid-production spike — I'm already in Production and want to test a specific mechanic or technical question quickly (~4 hours, no phase gate implications)

If "Skip — concept already proven": Ask (plain text, not a widget): "What evidence do you have that the concept works?" Record the one-line answer, then stop. Note: "Concept prototype skipped — evidence: [answer]." Suggest next step: /map-systems or /design-system [mechanic].

If "Mid-production spike": skip to the Spike Mode section below.