🎲 Dice Roller

Each die is generated independently with the browser's built-in random number function, scaled to the die size: the result is the floor of a random fraction multiplied by the number of sides, plus one. That produces a uniform whole number from 1 to the side count, with each face equally likely and no memory of previous rolls.

If a keep or drop rule is active, the rolled values are sorted and flagged. Keep highest marks the top N dice as kept, keep lowest marks the bottom N, drop highest removes the top N and drop lowest removes the bottom N. Only kept dice contribute to the subtotal; dropped dice are still displayed, greyed out, so you can see what was discarded.

Advantage and disadvantage work differently: the entire set is rolled twice as set A and set B, the two subtotals are compared, and advantage keeps the higher while disadvantage keeps the lower. Both sets stay visible.

The grand total is the kept subtotal plus the modifier. A roll where every kept die shows its maximum face is flagged as a critical when four or fewer dice are involved.

Select D6, set the number of dice to 4, leave the modifier at 0, and choose Drop Lowest with a count of 1. This is the classic method for generating a role-playing ability score, and it matches the built-in Stat Roll preset.

Suppose the four dice come up 5, 3, 6 and 2. The lowest value, the 2, is flagged as dropped and shown greyed out. The remaining three, 5, 3 and 6, are summed to give a subtotal of 14. With a modifier of 0 the grand total is 14.

The same four dice rolled straight, with no drop rule, would total 16. Dropping the lowest die is what shifts ability scores upward on average compared with rolling 3d6.

Now take the Attack Roll preset: one D20, no modifier. If it lands on 20, that equals the maximum possible for the kept dice, so the result is flagged as a critical. Switch the roll type to Advantage and the D20 is rolled twice, with the higher of the two kept as the total.

The result panel separates three numbers deliberately: the individual faces, the subtotal of kept dice, and the total after the modifier. When a rule has removed dice, always check the kept subtotal rather than mentally adding every face you can see, since the dropped dice remain on screen for transparency.

History is stored in your browser's local storage and holds your most recent rolls. It is per-browser and per-device, so it will not follow you to another machine, and clearing site data removes it. Nothing is sent to a server.

On fairness: the roller uses the browser's general-purpose random number generator. It is uniform and entirely suitable for games, but it is not a cryptographic source and should not be used where an adversary might benefit from predicting the outcome, such as gambling or key generation. There is also no seeding, so a roll cannot be reproduced later.

Finally, streaks are normal. Twenty dice will not produce a tidy spread, and a run of low rolls is a property of independent random events, not a fault in the tool.