2×d6 · Ready
Pick a die, choose how many, and roll. The total lands here.
Every fair die has the same simple arithmetic: each face carries a 1-in-faces chance, and the long-run average is the midpoint of its range. A d6 averages 3.5 per roll, a d20 averages 10.5. Add dice together and the distribution changes shape: one die is flat, two make a pyramid, three and more start to look like the famous bell curve. That is the central limit theorem, live at your game table.
It is also why game designers pick 2d6 when they want reliable middles with rare surprises, and a single d20 when they want drama: on one die, a critical hit is exactly as likely as a dull average roll.
d4
The oldest dice ever found are four-sided. The Royal Game of Ur, buried with Sumerian royalty around 2600 BC, came with tetrahedral dice, two corners tipped in shell to mark the throw. The shape barely tumbles, which is why every board game since has preferred the cube, and why gamers nicknamed it the caltrop: step on one barefoot and you will remember it.
d6
Cubic dice show up in the Indus Valley and Mesopotamia by around 3000 BC, and the design has barely changed since: opposite faces still add up to seven, a convention already common in Roman tesserae. It won because it works. A cube tumbles well, lands flat, and reads instantly, which is why it runs everything from backgammon to Monopoly to the craps table.
d8
Eight-sided dice are ancient too: octahedral examples survive from Ptolemaic Egypt and Rome, some inscribed with letters for divination rather than numbers for play. The modern d8 arrived in game shops with the first Dungeons & Dragons boxed sets in the mid-1970s, sold as part of the now-standard polyhedral family.
d10
There is no ten-faced Platonic solid, so the d10 is a pentagonal trapezohedron: ten kite-shaped faces meeting at two points. It earns its place because we count in tens. Roll two of them and you get a percentile throw, 1 to 100, which is how RPGs have resolved skill checks since the late 1970s. Its faces read 0 through 9, with 0 conventionally counted as ten.
d12
Plato assigned four of the five perfect solids to the elements and reserved the dodecahedron for the cosmos itself, writing in the Timaeus that the god used it "for embroidering the constellations on the whole heaven." Roman dodecahedral objects survive by the hundreds, though nobody agrees what they were for. As a die it is the underdog of the RPG set, prized by players precisely because so few rolls call for it.
d20
Twenty-sided dice are over two thousand years old. The Metropolitan Museum of Art holds a serpentine d20 from Ptolemaic Egypt, its faces carved with Greek letters, and similar icosahedra turn up across the Roman world. The modern one was rescued from obscurity in 1974, when Dungeons & Dragons made it the game's central resolution die. Rolling a natural 20 has since escaped the hobby entirely and become shorthand for perfect luck.
Up to six of the same type, with the total added up for you. Board games rarely need more, and 2d6 (two six-sided dice) covers everything from Monopoly to Catan. For mixed pools, roll each type in turn; the history below the roller keeps every throw.
Yes. Each face comes from the browser's cryptographic generator through rejection sampling, so a d20 face has exactly a 5% chance, a d6 face exactly one in six. Physical dice are usually worse: cheap ones have air bubbles and rounded corners that bias them measurably.
Dice notation: the first number is how many dice, the letter d, then how many sides. 2d6 is two six-sided dice added together; 3d8 is three eight-sided dice. The notation comes from tabletop role-playing games and is now the standard way to describe any dice roll.
Seven, on two six-sided dice. There are six ways to make it (1+6 through 6+1) out of thirty-six combinations, so it comes up one roll in six. Totals get rarer toward the edges: snake eyes (1+1) and boxcars (6+6) each appear once in thirty-six rolls. That pyramid of odds is the entire engine of craps and Catan.
Identical. The number is drawn first, by the same generator, and the animation then shows that result. The 3D die is a visualization of an already-decided roll, not a physics simulation whose outcome depends on rendering. Switch to 2D any time; it changes nothing but the look.
That is what the share link is for. Roll, copy the link, and drop it in the chat: everyone sees exactly the dice you rolled, not a claim about them. The roll history keeps the session's throws in order if anyone wants a recount.