D20 Roller
The D20 Roller rolls a twenty-sided die in your browser. The starting setting is 1d20 with a zero modifier. Each die uses a fresh secure random selection, and the result shows the individual faces followed by their sum. You can adjust the number of dice or add a whole-number modifier before rolling. The wheel animation represents the first die only; the textual result is the complete dice-pool outcome. Nothing is submitted to a game server or stored as a character record.
Your entries
20 entriesEach die rolls independently. The wheel shows the first die; the result lists every die and the total. Keep the face entries unchanged.
Equal chance for every entry. Repeated labels count as separate entries.
How to use this tool
- Choose the die size, number of dice and whole-number modifier. Keep the generated face list unchanged.
- Keep weighted mode and winner removal off for independent dice rolls.
- Choose the die size and select Roll the die.
- Copy the result if you need a record, then close the dialog or start another round.
Read this preset correctly
For a d20 check, read the raw die and the adjusted total separately. Your game determines whether a natural 1 or natural 20 has a special meaning. The starting configuration is shown beside the wheel. Keep the face list generated by the Die size selector unchanged: edited face lists are rejected in dice mode to prevent misleading totals.
Range and average for 1d20
Without a modifier, the smallest possible total is 1 and the largest is 20. The theoretical mean is 10.5. A mean describes the average over many rolls, not a promised result on the next attempt. Each die face has probability 1/20. With several dice, different totals can have different numbers of underlying combinations, so equal faces do not make all possible sums equally likely.
Set the pool and modifier before rolling
The controls support one to twenty dice of the selected standard size and an integer modifier between minus one thousand and one thousand. The modifier is added once to the total, not once per die. For example, two dice with a plus-three modifier produce first face plus second face plus three. Change the die size through its selector to regenerate the correct face list. Weights and winner removal must remain off because dice rolls are independent.
Keep game interpretation separate from the random roll
Read the individual faces when a rule distinguishes a natural result from an adjusted total. A modifier does not change which face was rolled. If your game calls for advantage, roll the required dice and apply the rule yourself; the ordinary summed total is not an automatic advantage result. Copy result preserves the displayed arithmetic as text. A shared configuration link preserves dice settings, not a predetermined future roll.
Frequently asked questions
What values can D20 Roller produce by default?
The untouched 1d20 preset produces totals from 1 through 20, with zero modifier. The result includes individual faces so you can check the arithmetic.
Is each face of the d20 equally likely?
Yes. Each independent die uses rejection sampling over 20 faces. Multiple-dice totals are not generally equally likely because some sums have more combinations.
Can I add a modifier to D20 Roller?
Yes. Set Modifier before rolling. It is added once after all die faces are summed. The result text shows the modifier and adjusted total.
Can a shared D20 Roller link reproduce the same roll?
No. It preserves the input configuration. Opening or rerolling the shared tool generates fresh random values; copy the result text when you need to share a completed roll.
Related wheels
Read the guide: Spin Wheel vs Coin Flip vs Dice.