What Dice Roller does
This dice roller replaces a physical set for tabletop games, quick decisions and probability demonstrations. Choose a die type from d4 up to d100, roll up to twenty at once, and add a fixed modifier for ability bonuses or similar adjustments. Every individual roll is listed alongside a summary of the total, the average, and the highest and lowest results, so you can spot a critical or check a group's spread without adding the numbers yourself.
Using Dice Roller
- 1
Choose the Dice type — d4, d6, d8, d10, d12, d20 or d100.
- 2
Set How many dice to roll at once, from 1 to 20.
- 3
Enter a Modifier if the roll needs a fixed bonus or penalty added to the total, or leave it at 0.
- 4
Click Roll and read the Result panel for the total, average and the extremes of the roll.
Where this helps
Tabletop RPG sessions over video call
Roll a d20 for an attack or a saving throw and read the individual result straight off the screen, with the modifier field handling ability bonuses automatically.
Board games missing a die
Lost a die from a boxed game is common — set the sides to match and the count to however many the game calls for, and the total appears instantly.
Teaching probability
Roll a large batch of d6 across several runs and compare the running average to the expected value of 3.5 to demonstrate the law of large numbers in a classroom.
Randomly assigning turn order
Roll one die per player and read down the individual results list to set the order, without a physical die getting knocked off the table.
Why 'd' notation exists
Tabletop gaming shorthand writes a die as 'd' followed by its number of faces, so 2d6 means roll two six-sided dice and add them, and 1d20+5 means roll one twenty-sided die and add five. The convention dates to tabletop wargaming and was popularised by Dungeons & Dragons, which is also why d20, d12, d10, d8 and d4 exist as physical objects at all — outside a d6, ordinary dice with those face counts are rare in everyday life. This tool follows the same shorthand: pick the sides, and the die type label above each result set shows exactly what was rolled.
How a fair roll is generated
Each die roll draws an integer uniformly from 1 to the number of sides using a seeded pseudo-random generator, the same one behind every other generator on this site. That means every face has an equal, independent chance on every roll — no face is more likely because of what came before, which is the same independence a physical die provides as long as it is not loaded or worn unevenly. The seed makes a specific roll sequence reproducible, useful for demonstrating a rules dispute or building a repeatable test case, but it also means the tool is not appropriate for anything where an opponent could benefit from predicting your roll in advance.
Worth knowing
- Roll several dice of the same type in one click rather than rolling one at a time and adding by hand — the total and average are computed for you.
- Use the modifier field for a fixed bonus rather than mentally adding it after the roll — it keeps the displayed total accurate.
- Note the seed if you need to demonstrate exactly how a specific roll came about.