Good game design doesn't happen in your head. It happens in tools — docs, diagrams, spreadsheets, simulators — and the quality of those tools directly affects the quality of your decisions. This guide covers the best game design tools across every discipline indie and mobile designers actually need: documentation, prototyping, systems design, economy balancing, and LiveOps planning. We'll also tell you where each tool falls short, so you can build a stack that actually fits how you work. TL;DR — Key Takeaways No single game design tool does everything. The best designers use a focused stack. For docs and GDDs: Notion or Confluence. For prototyping and flow: Figma or Miro. For systems and logic: Machinations or a custom spreadsheet. For game economy design, balancing, and LiveOps simulation: itembase is purpose-built for it. Free-to-play and live game designers specifically need a tool that handles currencies, progression, and event simulation — most general tools don't.…