WHITDice notation explained
Learn what expressions such as 2d6+3 and 4d6kh3 mean, from simple modifiers to rerolls and success pools.
WHIT3STAR / THE DICE APP
Math Rock Roller — Free Online Dice Roller
Roll dice. Track characters. Keep the adventure moving.
A free, browser-based dice roller for tabletop RPGs and system-specific rolls. Keep rolls, favourite shortcuts and character profiles together while you play.
Launch Math Rock Roller (new tab)
Explore Math Rock Roller
Find the right help for your next roll or adventure.
Supported game systems
Find your game and edition, see how its profile interprets rolls and check which rules remain in your hands.
Practical guides
Start with your first roll, understand percentile dice or compare advantage, disadvantage and dice pools.
Dice tools for the table
Standard and specialist dice
Roll d4, d6, d8, d10, d12, d20, percentile and Fate dice. Supported profiles configure their own dice; ordered tens-and-units pairs are available through Custom expressions.
Expressions and modifiers
Build rolls with multiple dice groups, modifiers, keep/drop, explosions, rerolls and success thresholds. Live explanations and selectable Expression Help examples keep the notation understandable.
Your characters and favourite rolls
Organise characters by campaign and save named rolls. Selecting a character brings its system and edition into the roller. General profiles are lightweight records, not full automated character sheets.
Save on your device
Data stays in the current browser. It does not sync automatically between devices and can be lost if browser storage is cleared. Export a JSON backup and review it before merging or restoring.
Play on mobile or desktop
Touch-friendly controls, readable results, reduced-motion support and instant rolling keep the interface focused. No application account is required.
Ready to play?
Getting started with the dice roller · Explore all four guides