GenerateRandomSearch

Custom Dice Roller

Not every game uses a standard six-sided die. Choose any number of sides from 2 to 1000, roll multiple dice at once, and add a flat modifier to the total.

What this generator does

Rolls dice with any number of sides you specify, rather than the standard polyhedral set, and keeps the session as you go: every roll, the running average against the average those dice should give, how often each face has appeared, and the exact odds of each total. Useful for board games with unusual dice, for teaching probability with a die that does not exist physically, and for any rule that calls for a size the shop does not sell.

How to use this tool

  1. Set the number of sides per die.
  2. Choose how many dice to roll.
  3. Optionally add a positive or negative modifier.
  4. Roll to see each result and the modified total.

Understanding the controls

Sides per die
Any whole number you enter, so a d3 or a d100 are both possible. Every face is equally likely regardless of the number you choose.
Number of dice
How many are rolled together. Each is rolled independently and shown separately as well as totalled.
Modifier
A flat number added to the total after the dice land. It moves the whole range of totals without changing the shape of the spread.
Seed
Empty for ordinary random rolls. Type anything to make the sequence repeatable — the same seed replays the same rolls in order. Deterministic, not cryptographic.
Show the exact odds
Puts the probability beside each roll: the chance of exactly that total and the chance of that total or better, both taken from the exact distribution for the dice you chose rather than from a simulation.

Common use cases

  • Tabletop RPGs with non-standard dice
  • Custom probability games
  • Classroom maths and probability exercises

Randomness and fairness

Every face is equally likely whatever number of sides you pick, because each die is drawn from your browser's cryptographic random source and values that would skew the range are discarded and redrawn. Give a seed and the source becomes a deterministic generator instead, repeating the same sequence for the same seed — reproducible rather than unpredictable, so it is for shared or repeatable sessions and not for anything that must not be guessable. Give a seed and the rolls come from a deterministic generator instead, replaying the same sequence for the same seed — deterministic, not cryptographic, so it suits a shared or repeatable session rather than anything that must be unguessable.

For how randomness is produced across the whole site, see how Generate Random works.

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