The Tongue of Dice

You have seen it on a spell scroll, in a monster's stat block, scratched in the margin of somebody's house rule: 1d20 + 5. Four symbols and a promise. Everyone else at the table reads it without pausing, the way you read a road sign. This is how they do it.

Dice notation says how many dice to roll, what kind, and what happens to the result. It is terse on purpose: it must be spoken across a table in one breath, over five people arguing about a door.

The Core Formula

Every roll is built from the same three parts, in the same order.

XdY

• X How many dice to roll. Leave it off and it means one.
• d Short for die.
• Y How many sides each die has.

So 1d6 is one six-sided die, 2d8 is two eight-sided dice added together, and d20 and 1d20 say exactly the same thing.

That is the whole grammar. Everything after this is a modifier hung off it.

The Dice at a Glance

A standard set holds seven dice, and each has a job it does more than any other. You learn them by touch long before you learn them by name. Examples come from the 2024 rules, SRD 5.2 [1].

Die	Sides	Where you meet it
d4	four	dagger damage, Potion of Healing (2d4 + 2), Magic Missile darts
d6	six	shortsword, Sneak Attack, ability scores
d8	eight	longsword, the Hit Die of seven classes out of twelve, Cure Wounds (2d8)
d10	ten	heavy crossbow, half of a percentile roll
d12	twelve	greataxe, the Barbarian's Hit Die
d20	twenty	every attack roll, saving throw and ability check
d100	percentile	the Wand of Wonder table, random trinkets

Adding Modifiers

Most rolls carry a modifier: a flat number applied after the dice have spoken.

Roll first. Then add. The dice decide; the modifier adjusts.

• 1d20 + 5 You roll a 14. Your result is 19.
• 2d6 + 3 The dice come up 4 and 2. Your result is 9.
• 1d8 - 1 You roll a 6. Your result is 5.

The order matters more than it sounds. A player who adds first and rolls second will eventually argue that a natural 20 was really a 15, and nobody wants to be at that table.

Total, or Each Die?

The roller on this site applies a modifier to total or to each die. Same notation, two answers.

2d6 + 3 to the total: roll 4 and 2, add 3 once. Nine.

2d6 + 3 to each die: roll 4 and 2, add 3 twice. Twelve.

Almost everything in fifth edition adds to the total. The famous exception is Magic Missile: three darts, and "a dart deals 1d4 + 1 Force damage" [1]. Point all three at one goblin and you roll 3d4, then add 3, not 1. Set the roller to to each and it keeps the books for you.

Keep, Drop, and Reroll

Past the basic form, notation picks up suffixes that say what to do with the dice once they land. The spellings below are the ones virtual tabletops such as Foundry VTT use [2]; other tools vary slightly.

4d6dl1 Roll four six-sided dice, drop the lowest, add the rest. This is the SRD's own "Random Generation" method: "Roll four d6s and record the total of the highest three dice" [1]. It lifts the average from 10.5 (plain 3d6) to 12.24, which is why your first-level fighter feels heroic and a straight 3d6 character feels like somebody's unlucky cousin.

2d20kh1 Roll two twenty-sided dice, keep the highest. This is Advantage. It raises your average roll from 10.5 to 13.83, about +3.3. Proficiency Bonus is +2 at levels 1 to 4 and +3 at levels 5 to 8 [1], so for the first half of a career, Advantage beats training.

2d20kl1 Roll two, keep the lowest. This is Disadvantage, and it costs exactly what Advantage gives: the average drops to 7.18.

What Advantage is really worth

The +3.3 is an average. Against a specific target number, the gain swings from almost nothing to a full +5. Computed exactly over all 400 pairs of d20s:

You need	Plain d20	Advantage	Disadvantage	Advantage is worth
2+	95%	99.8%	90.3%	+0.95
5+	80%	96.0%	64.0%	+3.2
8+	65%	87.8%	42.3%	+4.55
11+	50%	75.0%	25.0%	+5
14+	35%	57.8%	12.3%	+4.55
17+	20%	36.0%	4.0%	+3.2
20	5%	9.8%	0.3%	+0.95

"Worth" is the flat bonus that would give a plain d20 the same chance. Coin-flip rolls are where Advantage shines; at the extremes it barely moves the needle. Disadvantage mirrors it.

A Creature to Practise On

Every number on a stat block is notation, including the ones that do not look like it. Here is the Goblin Warrior from SRD 5.2 [1]. Read this one and you can read any of them.

Goblin Warrior

Small Fey (Goblinoid), Chaotic Neutral

AC 15 Initiative +2 (12)
HP 10 (3d6)
Speed 30 ft.

STR	DEX	CON	INT	WIS	CHA
8 (-1)	15 (+2)	10 (+0)	10 (+0)	8 (-1)	8 (-1)

Skills Stealth +6
Gear Leather Armor, Scimitar, Shield, Shortbow
Senses Darkvision 60 ft.; Passive Perception 9
Languages Common, Goblin
CR 1/4 (XP 50; PB +2)

Actions

Scimitar. Melee Attack Roll: +4, reach 5 ft. Hit: 5 (1d6 + 2) Slashing damage, plus 2 (1d4) Slashing damage if the attack roll had Advantage.

Shortbow. Ranged Attack Roll: +4, range 80/320 ft. Hit: 5 (1d6 + 2) Piercing damage, plus 2 (1d4) Piercing damage if the attack roll had Advantage.

Bonus Actions

Nimble Escape. The goblin takes the Disengage or Hide action.

Take it apart:

• HP 10 (3d6): the goblin in front of you has between 3 and 18 hit points. The 10 is the average (10.5, rounded down), printed so a busy GM need not roll.
• +4 to hit: Dexterity +2 plus Proficiency Bonus +2.
• 1d6 + 2: the scimitar's d6 plus that same Dexterity +2. Average 5.5, printed as 5.
• plus 1d4 with Advantage: the goblin's whole plan. It hides with Nimble Escape, attacks from hiding, and rolls 2d20kh1 to hit and 1d6 + 1d4 + 2 for damage. That is why goblins hurt more than their CR suggests.

Three Things Worth Knowing

Averages are written down for you

Where a stat block says 10 (3d6), the 10 is the average. Roll it or take it; both are correct, and taking it is faster when you have eleven goblins.

Advantage does not stack

Two sources of Advantage are still 2d20kh1. So are three. And any Advantage plus any Disadvantage cancel out: "A roll can't be affected by more than one Advantage, and Advantage and Disadvantage on the same roll cancel each other" [1]. You roll one plain d20, no matter how many of each you have collected.

Percentile is two dice

d100 is usually two ten-siders: one reads the tens, one the ones. A 4 and a 7 is 47. And per the rules, "Two 0s represent 100" [3], not nothing.

The Whole Language

Everything above, on one table. Tape it inside your side of the screen.

You see	You do
d20	roll one twenty-sided die
3d8	roll three eight-sided dice, add them
1d20+5	roll a d20, add 5
2d6+3	roll two d6, add 3 to the total
3d4+3 (Magic Missile)	roll three d4, add 1 to each
4d6dl1	roll four d6, drop the lowest
2d20kh1	roll two d20, keep the highest: Advantage
2d20kl1	roll two d20, keep the lowest: Disadvantage
1d100	roll percentile; 00 and 0 is 100

Try It

The roller on the dnddiceroller.com home page builds any of these from its controls: pick the count and the die, set the modifier to total or to each, and tick the option to drop (or reroll) the lowest or highest dice. It shows every die that landed, not just the total. For dice with physics, throw them on the 3D table.

One Last Rule If you cannot remember any of this, say the numbers out loud. "Two six-sided, plus three." Dice notation was written down to be spoken, and every table you will ever sit at already knows the sound of it.

This post is also a free booklet: download the PDF.

Table Talk

James: Honestly, I shout "roll the big one" and add whatever feels right.

Arthur: Roll first, then add. The rulebook has no objection to shouting.

James: Magic Missile. I add 1 once. Is that wrong?

Arthur: Each dart deals 1d4 + 1. Three darts at one goblin is 3d4 plus 3. You've been short-changing yourself two points a cast. Set the roller to to each and stop doing sums.

James: And Advantage is worth +3.3, so three sources of it makes me a god.

Arthur: It doesn't stack. Three sources is still 2d20kh1, and one Disadvantage cancels the lot.

James: Then Advantage is only really good when I need an 11.

Arthur: A full +5 there. Near a 2 or a 20 it barely moves. Save it for the coin flips.

James: And if I forget all of this mid-fight?

Arthur: Say it out loud. "Two six-sided, plus three." Every table knows the sound.

References

1. Wizards of the Coast. (2025). System Reference Document 5.2 (CC-BY-4.0): "Character Creation" (Random Generation), "Character Advancement", "Rules Glossary" (Advantage), "Spells" (Magic Missile, Cure Wounds), "Equipment" (Potion of Healing), "Monsters" (Goblin Warrior). https://www.dndbeyond.com/srd
2. Foundry Gaming. (n.d.). Dice Modifiers. Foundry Virtual Tabletop Knowledge Base. https://foundryvtt.com/article/dice-modifiers/
3. Wizards of the Coast. (2014). D&D Basic Rules, Introduction, "Game Dice". https://www.dndbeyond.com/sources/dnd/basic-rules-2014/introduction