What does “d6” mean?
In common tabletop-game notation, the letter d is followed by the number of sides on one die. Therefore:
- d4 means one four-sided die;
- d6 means one six-sided die;
- d8 means one eight-sided die;
- d10 means one ten-sided die;
- d12 means one twelve-sided die;
- d20 means one twenty-sided die.
This shorthand is a convention used by particular games and communities. It is not a universal manufacturing standard. When a game rule uses the notation, its rulebook is the final authority.
How to read “3d8 + 5”
The usual expression has three parts: number of dice + d + number of sides + modifier. So 3d8 + 5 means rolling three eight-sided dice, adding the three results, and then adding 5. If the dice show 2, 6, and 7, the calculation is 2 + 6 + 7 + 5 = 20. If no number appears before the d, readers normally understand it as one die, so d20 is shorthand for 1d20.
Minimum and maximum results
For a basic expression with positive dice and a fixed modifier:
minimum = number of dice × 1 + modifier
maximum = number of dice × number of sides + modifier
For 3d8 + 5, the minimum is 8 and the maximum is 29. The formula assumes ordinary numbered dice and a fixed modifier. Special rules such as rerolls, dropped dice, exploding dice, advantage, or substituted results need their own explanation.
Why rolling more dice changes the distribution
One fair d6 has six possible results, and each individual face has probability 1/6 under the fair-die assumption. But the totals from two dice are not equally common. A total of 7 can be made in more combinations than a total of 2, so 7 is more likely when rolling 2d6. This is why 1d12 and 2d6 are not interchangeable even when their ranges overlap.
When publishing a probability table, DICEWIKI will show the assumptions and count equally likely underlying outcomes rather than presenting only a visual curve.
What is d100 or percentile notation?
Some rules use d100 to describe a result from 1 to 100. In many tabletop games, this is generated with two ten-sided dice: one die supplies the tens digit and the other supplies the ones digit. A roll of 7 and 1 can represent 71; two zeroes are commonly interpreted as 100 when the rules define the dice as percentile dice. Always check whether a displayed “00” means 0, 100, or a range label before interpreting the result.
Common notation mistakes
In d20, 20 describes the number of sides, not the number rolled. In 4d6, the 4 means four dice and the 6 means six sides per die. Many games use similar notation, but modifiers and special instructions can differ, so DICEWIKI will identify the source game when notation is quoted from a rulebook.
Try the related tools
- Dice roller
- Dice probability calculator
- What is a die?
- Dice probability basics
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