Tabletop dice

Dice notation explained

Published 25 May 2026 · 6 min read

Tabletop games often describe dice with short codes like d20, 2d6 or 1d100. Once you know the pattern, the notation is easy: the number before the d tells you how many dice to roll, and the number after the d tells you how many sides each die has.

The basic pattern

NdX means "roll N dice, each with X sides." So 1d20 means roll one twenty-sided die. 2d6 means roll two six-sided dice and add them together. If the first number is missing, people usually mean one die: d6 is the same as 1d6.

Common dice and what they are for

Multi-dice rolls

When notation starts with a number higher than one, roll that many dice and add them. 3d6 means roll three six-sided dice. 4d6 means roll four six-sided dice. Some rules add an extra instruction, such as 4d6 drop lowest, where you roll four dice, remove the lowest die, and add the remaining three.

Spinnit has presets for 2d6, 3d6, 4d6 drop lowest, d10 and d100.

Modifiers: plus and minus numbers

You will often see rolls like 1d20 + 5 or 2d6 - 1. Roll the dice first, add them if there is more than one, then apply the modifier. A 1d20 + 5 roll that lands on 12 becomes 17. A 2d6 - 1 roll with dice showing 4 and 3 becomes 6.

Advantage and disadvantage

Some games ask you to roll two d20s and keep one. With advantage, roll two d20s and use the higher result. With disadvantage, roll two d20s and use the lower result. The notation may be written informally as "roll with advantage" rather than as a pure dice code.

Percentile dice and d100

A d100 result gives a number from 1 to 100. Physical tables often roll two ten-sided dice: one for the tens digit and one for the ones digit. Online, a d100 roller can return the percentile result directly. Use it for loot tables, random encounters, event odds or any rule that asks for a percentage-style roll.

Which online dice tool should I use?

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-> Dice Roller

-> Dice Roller Tools hub

-> 4d6 drop lowest guide

-> Online dice roller for tabletop games