Dice Roller & Coin Flip

How to use Dice Roller & Coin Flip

1. Open the Dice roller tab, choose how many dice and how many sides.
2. Press Roll to see each die, the sum, the average and the highest and lowest values.
3. Switch to Coin flip and press Flip coin to get heads or tails.
4. Use the history and tally to track results, and reset them whenever you like.

What the dice notation means

Tabletop games use shorthand such as 3d8, meaning three dice with eight sides each. The first number is how many dice to roll, and the number after the d is how many faces each has. A d20 produces a number from 1 to 20 and is common in role-playing games for checking whether an action succeeds. A d6 is the standard cube found in most board games.

The sum of several dice does not spread evenly. Rolling 2d6 gives 7 most often because six of the thirty-six combinations add to 7, while 2 and 12 each have only one combination.

Using the coin flip well

A coin flip is the simplest way to settle a two-way decision. Agree what heads and tails mean before flipping, otherwise people tend to reinterpret the outcome. If you feel disappointed by the result, that reaction can be useful information about what you actually wanted.

The tally shows the law of large numbers in action. After 10 flips the split may be 7 to 3, but after hundreds it moves close to even. It does not correct itself after a streak; each flip is independent of the last.

Handy uses

• Play board games when dice are lost or you are playing remotely.
• Run tabletop role-playing sessions with a quick online roll.
• Teach probability in a classroom with fast repeated trials.
• Decide who starts a game or who gets the last slice.
• Try out house rules by watching how sums are distributed.

Limits

The roller handles up to 20 dice at once and does not apply modifiers, advantage or exploding dice. Results and history are not saved after you close the page.

Why use this dice roller & coin flip tool

• All common dice. d4, d6, d8, d10, d12 and d20, which covers most board games and tabletop role-playing games.
• Sum and statistics. See the total, average and extremes for each roll, plus a history of the last 15 rolls.
• Coin with tally. Heads and tails counts with percentages show how results even out over many flips.
• Cryptographic randomness. Rolls use your browser’s secure random generator with no bias.

Frequently asked questions

More free tools