Dice Roller

Features

• Full dice notation including keep-highest and keep-lowest
• Advantage and disadvantage
• Exploding dice
• Session statistics and roll history
• Cryptographic randomness, not Math.random

How to use it

1. Type notation such as 3d6+2, or tap a preset.
2. Choose advantage or disadvantage if you need it.
3. Press Roll.
4. Individual die results are shown beneath the total.

Reading dice notation

The basic form is NdS: N dice with S sides each. 3d6 rolls three six-sided dice and sums them. Modifiers are added after: 3d6+2 adds two to the total, 1d20-1 subtracts one. This is the notation Dungeons & Dragons popularised and it is now near-universal across tabletop games.

The keep notation handles the common case of rolling extra dice and discarding some. 4d6kh3 rolls four six-sided dice and keeps the highest three, the standard method for generating D&D ability scores, because discarding the lowest die shifts the average from 10.5 up to about 12.24. 2d20kl1 keeps the lowest of two, which is what disadvantage does.

Multiple dice produce a bell curve, and this matters more than people expect. A single d20 is flat: every result from 1 to 20 is equally likely. Three d6 sum to between 3 and 18 but cluster heavily around 10 and 11, with a 1-in-216 chance of either extreme. Games that use 3d6 instead of 1d20 are choosing predictability, the average outcome dominates and dramatic swings are rare.