D&D Dice Roller with Notation

What This D&D Dice Roller Does

This page rolls the dice a Dungeons & Dragons table actually uses, written in standard dice notation. Enter a roll such as 2d6+3, press Roll and you see each individual die, which ones were kept or dropped, and the total with your modifier. It is meant for the rolls that need more than one button: spell damage, sneak attack, healing potions and ability scores. If you only need a single twenty-sided die with an advantage toggle, the dedicated D20 roller is the faster tool, and the main dice roller handles any single die type from D4 to D100.

How Dice Notation Works

A notation is the number of dice, the letter d, the number of sides, and an optional modifier. In 2d6+3 you roll two six-sided dice, add them together and add 3. The tool understands a few extensions that D&D players use all the time.

Notation	Meaning	Range
1d20+5	One twenty-sided die plus 5	6 to 25
2d6+3	Two six-sided dice plus 3	5 to 15
8d6	Eight six-sided dice, summed	8 to 48
4d6dl1	Roll four d6, drop the lowest one	3 to 18
2d20kh1	Roll two d20, keep the highest one (advantage)	1 to 20
2d20kl1	Roll two d20, keep the lowest one (disadvantage)	1 to 20
1d8+1d6+2	Several terms added together	4 to 16

Terms can be combined with plus and minus, so a longsword hit with a bonus die, such as 1d8+1d4+3, is a single entry. Spaces are ignored and capital or lowercase d both work. If something cannot be read, the tool tells you instead of guessing.

Common D&D Rolls and Their Notation

Weapons and spells list their dice in the same notation. Some typical examples from the 5th edition rules:

• Dagger: 1d4 plus your ability modifier.
• Longsword: 1d8 plus your modifier, or 1d10 when wielded in two hands.
• Greatsword: 2d6 plus your modifier.
• Greataxe: 1d12 plus your modifier.
• Fireball: 8d6 fire damage at the spell's base level.
• Potion of healing: 2d4+2 hit points.
• Sneak attack: extra d6s that grow with rogue level, for example 3d6 for a rogue who has earned three of them.

Always check the exact entry in your own rulebook or the Dungeon Master's table rules, since editions, class features and magic items change the numbers. For what each die means in play, see D&D dice explained, and for the full set including the D100 and the physical shapes, read the dice types guide.

Critical Hits and Damage Dice

On a critical hit in the 5th edition rules you roll the weapon's damage dice twice and then add your modifier once. A longsword attack that normally uses 1d8+3 becomes 2d8+3. Type that into the roller as a single entry. With several damage terms, such as a rogue's weapon die plus sneak attack dice, all dice are doubled, but fixed modifiers are not. A natural 20 on the attack die happens on 5 % of single rolls, and with advantage it happens on 9.75 % of attack rolls (39 of 400 combinations), because either of two dice can show it. The advantage and disadvantage guide shows the exact tables.

Advantage and Disadvantage in Notation

Advantage means rolling two d20 and keeping the higher number; disadvantage means keeping the lower. In notation these are 2d20kh1 and 2d20kl1, which you can type or select with the preset buttons above. The tool marks the dropped die so you can see both results. Add your modifier after the notation, for example 2d20kh1+4. The averages are about 13.83 with advantage and about 7.18 with disadvantage, against 10.5 for a single d20, so advantage is worth roughly 3.3 points on average, with the biggest effect when the target is near the middle of the range.

Rolling Ability Scores: 4d6 Drop Lowest

A classic rolled method for generating the six ability scores is to roll four six-sided dice, drop the lowest and add the other three. Do it six times, once for each ability, and assign the totals as you like. In the tool this is 4d6dl1, and the preset button runs it. Counting all 1,296 possible outcomes gives these exact probabilities for one roll:

Score	Chance	Score	Chance
3	0.1 %	11	11.4 %
4	0.3 %	12	12.9 %
5	0.8 %	13	13.3 %
6	1.6 %	14	12.3 %
7	2.9 %	15	10.1 %
8	4.8 %	16	7.3 %
9	7.0 %	17	4.2 %
10	9.4 %	18	1.6 %

The average score is about 12.24, compared with 10.5 for plain 3d6. The chance of rolling 15 or higher on a single score is 23.1 %, and 16 or higher is 13.0 %. The chance of 8 or lower is 10.5 %. Over six scores the typical set adds up to roughly 73, which is why rolled characters tend to be somewhat stronger than characters built from the standard array of 15, 14, 13, 12, 10 and 8. Many groups allow a re-roll of an extremely weak set, but that is a table rule: ask your Dungeon Master before you roll. More background on the shape of these distributions is in dice probability explained.

Handling Big Pools: 8d6 and Beyond

Spells such as Fireball call for many dice at once. The roller shows all eight dice so that the table can see the roll, and the total appears below. The average of 8d6 is 28, and about 64 % of all rolls fall between 24 and 32, but any total from 8 to 48 is possible. Damage often depends on a saving throw, where a successful save halves the damage; do the halving after adding the total, and round down as the rules specify. When several creatures are affected, one damage roll applies to all of them.

Everyday Rolls: Initiative, Hit Dice and Group Checks

Not every roll is an attack. Initiative is a d20 plus your Dexterity modifier, so a character with a +2 modifier enters 1d20+2. Hit dice are spent during a short rest: you roll the die for your class, such as 1d8 for a cleric, and add your Constitution modifier, so the notation is 1d8+2 for a +2 modifier. Monster groups in many adventures roll one shared initiative, which you can do with a single 1d20 and a note of who acts when. Percentile tables use 1d100, and a wild magic or random encounter table works the same way: roll, read the line, move on. If your Dungeon Master asks for a group check, everyone rolls a d20 and adds their own modifier, so each player can enter their own notation on their own device.

When a roll depends on rest or level, the modifier is the part that changes. Keep your usual rolls in a note, for example 1d20+5 for a trusted skill and 1d8+3 for your main weapon, and paste them in whenever you need them. The roll history under the tool keeps the most recent rolls for the session, which helps when someone asks what you rolled two turns ago.

Is the Roller Fair?

Each die uses your browser's built-in random number generator, so every face has the same chance on every roll and rolls do not influence each other. That is the right tool for a game. It is not meant for gambling or for security uses. If your group prefers physical dice, you can use this page as a check or a backup, and the guide on fair dice shows how to test a real die at the table.

Tips for Using an Online Roller at the Table

• Announce the notation. Say "2d6 plus 3" before rolling so that everyone knows what is being asked for.
• Read the dice, not just the total. Some features care about individual dice, such as a natural 20 or a die that shows a 1.
• Share a screen in remote games. One visible roll avoids arguments, or let each player roll their own and post the result in chat.
• Use the history. The list under the roller keeps your recent rolls for the session, so a disputed result can be checked.
• Rolling in secret. A Dungeon Master who rolls behind a screen can do the same with the roller on their own device.

For games beyond D&D that use the same dice, tabletop RPG dice explains the common systems, and the board game dice page covers presets for classic board games.