FairMath RPG Progression Calculator
Calculate RPG stat progression using the “FairMath” formula, made popular by ChoiceScript games and modern interactive fiction. Instantly compare FairMath vs linear math with a table and chart.
Perfect for game designers, writers, and narrative devs.
What is FairMath? (Click to expand)
- What is FairMath in RPGs and ChoiceScript?
- FairMath is a non-linear progression formula: big stats change less as they approach 0 or 100, keeping stats “fair.” Example: FairMath(+20%) on 50 gives 60, but on 80 only gives 84.
- How is FairMath different from normal math?
- Normal math adds/subtracts a fixed percent; FairMath’s changes shrink as you near the edges. It’s perfect for games needing bounded, balanced stats.
- Where is FairMath used?
- Most famously in ChoiceScript (by Choice of Games), but any RPG, story, or stat-based game can use it.
- What’s the FairMath formula?
- Increase:
new = old + (100 − old) × (change ÷ 100)
Decrease:new = old − old × (change ÷ 100) - Can I simulate multiple steps?
- Yes! This calculator supports up to 20 repeated applications.
- What’s this tool for?
- Planning RPG stat growth, balance, and player progression. Try different values and see the effect!