What Does 2d6 Mean? How to Read Dice Notation, and the Dice Used in Tabletop RPGs

How to read dice notation: NdX+M

Dice notation is a way of writing on one line “which kind of die, how many to roll, and what to add”. The basic form is NdX+M, where each part means the following.

• N: how many dice to roll. With just one, it’s sometimes left out and written as d6.
• d: short for die (or dice). Writing it in capitals, as 2D6, means the same thing.
• X: the number of faces on the die. 6 for a six-sided die, 20 for a twenty-sided one.
• +M: a fixed value added to (or subtracted from) the total. 2d6+3 means add 3 to the total.

So 2d6 is an instruction to “roll two six-sided dice and add them up”. People say it in different ways, such as “two-dee-six” or “two d six”, but the meaning is the same.

Why 2d6 instead of 1d12?

1d12 (1–12) and 2d6 (2–12) cover almost the same range. 2d6 is still far more widely used because the results are distributed differently.

• With a single die (1d6 or 1d20), every result is equally likely. Luck plays a big part and extreme results come up often.
• Adding two or more dice gives a bell-shaped distribution where middle values are more likely. With 2d6, a total of 7 is the most likely, and 2 and 12 are the least likely.
• A bell-shaped distribution means “usually about average, occasionally way off”, so modifiers such as +2 carry more weight.

On the other hand, when you want one lucky roll to matter more than skill, a single die like 1d20 suits better. Which one a rule uses completely changes what one point of modifier means. Probabilities and expected values for each total are covered in a separate article.

Types of polyhedral dice and what they’re used for

RPG dice sets are usually sold as a set of seven: d4, d6, d8, d10, a d10 for tens, d12 and d20. That covers most notation.

• d100 is usually not a special hundred-sided die but two d10s of different colors, one read as the tens digit and the other as the ones digit. 00 with 0 counts as 100.
• d10s come marked 0–9 or 1–10. Most rules read 0 as 10, but it’s safest to check at your table.
• d66 isn’t a special die but a way of reading two d6s, deciding in advance that the one you read first is the tens digit. Decide which is the tens digit before you roll.

Recreating multiple dice with a single d6

Even without real dice, if you can roll one six-sided die you can recreate 2d6 or 3d6. Rolling one die several times gives the same probabilities as rolling several dice at once.

1. 1

   Decide how many rolls you need first

   Two rolls for 2d6, three for 3d6: announce the number of rolls before you start. Adding rolls afterwards looks as though you added them after seeing the result.

2. 2

   Roll one at a time and note each result

   The browser dice tool rolls one six-sided die per button press and shows the result as a number. Write down each result as you go.

3. 3

   Add them up and apply the modifier

   Total the results you noted, and add any modifier such as the +3 in 2d6+3 at the end. Handle negative modifiers (such as −1) at the same point.

4. 4

   For d66 or d100, decide which digit is which

   Decide that the first roll is the tens digit and the second the ones digit before rolling. Deciding after rolling means you’re choosing the result.

When you need something other than 1–6, enter options one per line in the spinner tool and it creates a wheel divided equally into that many parts. Four items for a d4, twenty for a d20: you can use it in place of dice with different numbers of faces.

House rules to agree on at your table

Even when the notation is shared, how it’s handled varies by rule system and table. Agree on the following before you start and play won’t grind to a halt.

• Rerolls: if a die falls off the table or lands cocked, do you reroll or accept it?
• Criticals and fumbles: whether a 20 on 1d20 is an automatic success and a 1 an automatic failure depends on the rules.
• Doubles: some rules give doubles on 2d6 a special meaning. Decide whether you use that first.
• Rounding: when damage is halved, do you round up or down? The rulebook takes priority.
• Announcing online: agree on where results are recorded (written in the chat, kept in a shared note).

When you’re choosing people rather than resolving checks, such as deciding turn order or who does what, amidakuji (ghost leg) or a spinner is easier to explain than dice. You don’t have to think about how to break ties, so play keeps moving.

FAQ

What does 2d6 mean?

It means roll two six-sided dice and add the results. d stands for die; the number before it is how many dice, and the number after it is how many faces. 2d6 gives a result from 2 to 12, with 7 the most likely total. If there’s a number after it, as in 2d6+3, add that value to the total.

Can I roll 2d6 or 3d6 with only one die?

Yes. Rolling one die twice and adding the results gives the same outcome as 2d6, with the same probabilities. The browser dice tool rolls one six-sided die at a time, so decide how many rolls you need first, roll them one at a time and add up the results. As long as you don’t add rolls after the fact, there’s no problem.

How do I read notation like 4d6b3?

It means roll four six-sided dice and total only the three highest. Some rules write the same operation as kh3 (keep highest 3) or dl1 (drop lowest 1). It’s used when you want to nudge the average up a little, such as when generating ability scores. Notation varies between rules, so check the explanation the first time you see it.

Does d100 use a hundred-sided die?

Usually it uses two d10s. The common method is to take two of different colors and read one as the tens digit and the other as the ones digit. 0 with 0 counts as 100. Deciding which one is the tens digit before rolling is the trick to avoiding arguments over the result.