How to use the dice roller
Pick how many dice, how many sides, and a bonus if you have one, then press Roll. The dice tumble across the table and settle, and the total appears over them. You can also type the whole roll in the box, such as 3d6+2, and the buttons follow along. The Quick rolls cover the usual jobs: one die, two dice for a board game, a twenty-sided die with advantage or disadvantage, and four dice with the lowest dropped.
Next to the roller are two more views. Dice odds is a dice probability calculator: it gives the exact chance of any total, of a total or more, or of a total or less, for any set of dice. Watch the rolls throws your dice thousands of times and stacks the totals so you can see the odds appear.
Dice notation
The box takes the short form used in tabletop games. The number before the d is how many dice, and the number after it is how many sides.
| You type | It means |
|---|---|
| d20 | one twenty-sided die |
| 2d6+3 | two six-sided dice, add 3 |
| 4d6dl1 | four six-sided dice, drop the lowest one |
| 4d6kh3 | four six-sided dice, keep the highest three (the same roll) |
| 2d20kh1 | two twenty-sided dice, keep the higher (advantage) |
| 2d20kl1 | two twenty-sided dice, keep the lower (disadvantage) |
| d4+d6+d8 | one of each, added together |
| 2d8-d4 | subtract a die |
| d% | a percentile die, the same as d100 |
How a roll is picked
Each die is its own draw. The page asks your browser for secure random numbers, the kind built for cryptography, and turns each one into a face. A six-sided die needs one of six equal outcomes, and a random number from your browser does not split evenly into six, so the few values that would favor the low faces are thrown away and drawn again. Every face of every die gets exactly the same share.
Only after all the faces are drawn does anything move. The page works out a throw that ends on those faces: where each die lands, how many times it turns, how many times it bounces. A harder throw or a longer roll cannot change a face, because the tumble is a replay of a decision already made. Dropped dice are struck through, and the total counts only the dice that were kept.
Why totals bunch up
One die is flat: every face is equally likely. Add a second die and the middle gets crowded. With two six-sided dice there are 36 ways to roll, and 6 of them make 7, so a 7 turns up 1 time in 6 (16.7 percent). A 2 or a 12 can happen only one way each, 1 time in 36.
chance of 2 on 2d6 = 1 way ÷ 36 = 2.8%
average of n dice with s sides = n × (s + 1) ÷ 2
The more dice you add, the tighter the total clusters around its average. Three six-sided dice make 10 in 27 of their 216 ways (12.5 percent), and a total of 3 or 18 comes up only 1 time in 216. That is why adding dice makes extreme totals rare, while one big die swings wildly.
Advantage, disadvantage and dropping dice
Many games let you roll more dice than you count. Keeping the highest of two twenty-sided dice raises the average from 10.5 to 13.825, and keeping the lowest lowers it to 7.175. Rolling four six-sided dice and dropping the lowest averages 12.24, against 10.5 for three dice.
The effect depends on the target. Say you need 15 or more on a twenty-sided die with a +5 bonus. A single roll makes it 55 percent of the time, advantage 79.75 percent, and disadvantage 30.25 percent. The Dice odds tab shows all three side by side for any set of dice.
The dice themselves
The four-, six-, eight-, twelve- and twenty-sided dice are the regular solids: the tetrahedron, cube, octahedron, dodecahedron and icosahedron. Each can be made fair because all its faces are alike. The ten-sided die is a pentagonal trapezohedron, with ten kite-shaped faces. The page draws every one of them as a solid, with the numbers lying on each face the way they do on a real die.
- On a standard six-sided die, opposite faces add up to 7. The pips on this page follow that rule.
- A four-sided die has no face that lies flat on top, so it is read at the corner that points up. Each face shows its three corner numbers.
- A d100 is two ten-sided dice, one numbered in tens from 00 to 90 and one numbered 0 to 9. A 00 with a 0 is read as 100.
- A die with any other number of sides, such as a d30 or a d7, is drawn as a cube that shows the number you rolled on top.
Where the numbers come from
- Random numbers: the Web Cryptography API,
Crypto.getRandomValues()(MDN Web Docs).Math.random()is not used for any roll, because browsers describe it as not cryptographically secure. - Dice shapes and numbering: the regular solids, the pentagonal trapezohedron, the opposite faces of a six-sided die, percentile dice and the way a four-sided die is read all follow Wikipedia's articles on Dice, Platonic solid and Pentagonal trapezohedron.
- Totals, averages, advantage and dropping dice are exact counts, checked against counting every possible roll by hand for small sets and against simulation for large ones.
No laboratory has tested or certified this roller. Do not use it for gambling, lotteries or any drawing the law regulates.
Tips and common mistakes
- Dice have no memory. After three sixes in a row the next roll is still 1 in 6.
- For the same range, many small dice give steadier results than one big die. 3d6 and d20 can both reach 18, but 3d6 does it 1 time in 216 and a d20 does it 1 time in 20.
- A bonus shifts every total by the same amount. It does not change how likely each one is.
- Check what you are keeping. 4d6kh3 and 4d6dl1 are the same roll, and 4d6kl3 is a much worse one.
Questions
Are the rolls fair?
Yes. Each die is drawn from your browser's secure random generator before it moves, and values that would favor some faces are thrown away and drawn again. Open Watch the rolls to see thousands of rolls settle onto the exact odds.
How does advantage work?
You roll the die twice and keep the higher result. Disadvantage keeps the lower. Pick Advantage in Quick rolls, or type 2d20kh1 for advantage and 2d20kl1 for disadvantage.
How do I roll a d100?
Press d100 in Sides, or type d%. The page rolls two ten-sided dice, a tens die and a ones die, and reads 00 with 0 as 100.
Can I roll a die with an odd number of sides?
Yes, from 2 to 1,000 sides. The result is exact, and the page draws it as a cube with your number on top, since a real d7 or d30 has no standard shape.
Are my rolls saved or sent anywhere?
No, unless you press Share on Facebook or Copy the link. Those save the last roll (the dice, the results and the total) on AerialQuote for 90 days so the link can show it. The TikTok video is made in your browser and is not uploaded.
How do I post a roll on Facebook or TikTok?
After a roll, press Share. Share on Facebook posts a link with a picture of your dice. Make a video for TikTok records a 9:16 replay of the tumble with the sound, then you download it or send it to TikTok from your phone's share sheet. Both carry the address aerialquote.com/dice-roller so friends can roll their own.
Can I use it for gambling?
No. It is for games with friends, classes and quick decisions. If money or the law is involved, use dice and rules that are approved for that.