AnyDice
An online dice-probability tool with a compact language for pools, keep-high or keep-low rules, exploding dice, rerolls, and custom outcomes, presented as tables, graphs, or CSV.
Why it’s here
Tabletop, RPG, and loot-system designers can compare success rates, variance, edge cases, and modifier effects before prototyping instead of judging a mechanic from a handful of manual rolls.
Best fit
Prototype systems, stories, and interactions, then validate them with real players.
Before you commit
Complex programs fail when they exceed the server's roughly five-second computation limit, and a model cannot replace how real players perceive risk; no public source or explicit commercial-use terms are posted, so redistribution of code, site content, or service output requires separate confirmation.