D20 Dice Roller
Roll virtual D20 dice online with our free 20-sided dice roller for DND and tabletop RPGs. Simulate up to 15 D20 dice with totals, averages, frequency charts, and individual results.
About This Calculator
The D20 Dice Roller is a free online tool for rolling 20-sided dice, designed for tabletop RPG players especially Dungeons & Dragons enthusiasts. Roll up to 15 D20 dice simultaneously and view comprehensive results including total sum, average, distribution charts, and individual roll values.
The D20 die is an icosahedron, a polyhedron with 20 triangular faces. Each face is equally likely with a 5% probability. Our virtual roller uses cryptographically-inspired random number generation to simulate fair dice throws. The frequency chart displays how often each value appeared, while the individual breakdown shows every die's result.
Regional Notes
Global: The D20 is the signature die of Dungeons & Dragons, the world's most popular tabletop RPG. It determines success or failure of actions during gameplay, from attacking monsters to persuading NPCs. The D20 system is used across many RPGs worldwide including Pathfinder in the US and Warhammer in the UK.
Frequently Asked Questions
What is a D20 dice roller?
A D20 dice roller is a virtual tool that simulates rolling 20-sided dice (D20), commonly used in tabletop RPGs like Dungeons & Dragons. It generates random numbers from 1 to 20 for each die, with each value having an equal 5% probability of appearing.
How do D20 rolls work in Dungeons and Dragons?
In Dungeons & Dragons, you roll a D20 to determine success or failure of actions. The target number (e.g., Armor Class) must be met or exceeded. You roll the D20, add any relevant modifiers (ability scores, proficiency bonuses), and if the total equals or exceeds the difficulty class, the action succeeds. A natural 20 is an automatic success, while a natural 1 is an automatic failure.
What shape is a D20 die?
A D20 die is an icosahedron, which is a polyhedron with 20 triangular faces and 12 vertices. This shape makes it the most spherical of the standard polyhedral dice, allowing it to roll further than other dice designs.
Can I roll multiple D20 dice at once?
Yes, our D20 dice roller supports rolling 1 to 15 D20 dice simultaneously. The calculator shows the total sum, average, minimum and maximum values, frequency distribution chart, and individual roll breakdowns for each die.
What games use D20 dice?
D20 dice are primarily associated with Dungeons & Dragons (D&D), but they are also widely used in other tabletop RPGs including Pathfinder, Starfinder, Shadowrun, and many homebrew games. The D20 is the signature die of the d20 System used by many roleplaying games.
Is the D20 dice roller fair and random?
Yes, the calculator uses JavaScript's Math.random() to generate uniformly distributed random numbers between 1 and 20. Each face has an equal 5% chance of being rolled, making it equivalent to a physical fair D20 die.
What is the probability of rolling a 20 on a D20?
The probability of rolling any specific number on a fair 20-sided die is 1/20 or 5%. This means the chance of rolling a natural 20 is 5%, the same as rolling any other single number from 1 to 20.