How the Custom Dice Roller Works
Set the number of sides and how many dice you want, then press the button. Every die result is listed alongside the total. It covers the moment you cannot find a six-sided die, a board game box is missing a piece, or a tabletop session needs a d20 or a d100. Press the button again to roll the same setup as many times as you like.
The numbers shown with each roll
The total is the sum of every die. The average is that total divided by the number of dice. The expected total is what the sum averages out to in theory: for K dice with N sides it is K × (N + 1) ÷ 2, so two six-sided dice give 2 × (6 + 1) ÷ 2 = 7. A single roll landing above or below that figure is entirely normal; the more you roll, the closer the running average creeps to the expected total. The possible range runs from every die showing 1 to every die showing its highest face, which is the dice count up to the dice count times the sides. Average and expected total are both computed from the raw values rather than from a rounded display, then shown to two decimal places.
Input limits
Sides accept 2 through 1,000 and the dice count accepts 1 through 20. Fewer than 2 sides or more than 1,000 shows a message instead of a roll, and a dice count above 20 is trimmed to 20 with a note in the result. Each die draws an integer from 1 up to its number of sides with equal probability.
Frequently Asked Questions
For K dice with N sides it is K × (N + 1) ÷ 2. Two six-sided dice give 2 × (6 + 1) ÷ 2 = 7, and the average of many rolls drifts toward that number.
Up to 20. A larger number is trimmed to 20 automatically and the result shows a note explaining the adjustment.
Yes. Sides can be set anywhere from 2 to 1,000, so the d4, d8, d20, and d100 used in tabletop RPGs all work.