An online dice roller lets you roll any standard die — d4, d6, d8, d10, d12, d20, or d100 — instantly, with no dice bag required. Pick the die type and how many to roll, and get each individual result plus the total, whether you need a single d20 attack roll or a fistful of 8d6 for a fireball.
Virtual dice shine when physical dice are impractical: playing tabletop RPGs over video chat, board games with missing dice, classroom probability lessons, or quick decisions anywhere. Every roll is generated fresh and independently, so the odds on each throw are exactly what they would be with a fair physical die.
Dice Types and Tabletop Gaming
The seven-dice set popularized by Dungeons & Dragons covers nearly every tabletop need:
- d4 (tetrahedron): small weapon damage, like a dagger
- d6 (cube): the classic die — board games, fireballs (8d6), character stats (4d6 drop lowest)
- d8 (octahedron): longsword damage, hit dice
- d10 (pentagonal trapezohedron): percentile games and d100 rolls, paired with a tens die
- d12 (dodecahedron): greataxe damage, the barbarian’s friend
- d20 (icosahedron): the heart of D&D — attacks, saving throws, ability checks
- d100: rolled as two d10s (tens and ones), used for loot tables and wild magic
Standard notation reads "NdX + modifier": 3d6+2 means roll three six-sided dice and add 2 to the total. A natural 20 — rolling 20 on the raw d20 — is a critical hit in D&D 5e.
The Probability of Common Rolls
Single dice are uniform — every face has equal probability (5% per face on a d20). Sums of multiple dice are not: middle totals come up far more often because more combinations produce them.
For 2d6 (36 combinations): a 7 is the most likely sum at 16.7% (six ways to roll it), while 2 and 12 happen just 2.8% of the time each (one way). The distribution forms a triangle peaking at 7 — the reason 7 rules the craps table and the Settlers of Catan board.
D&D 5e advantage (roll 2d20, keep the higher) shifts the average roll from 10.5 to about 13.82 — worth roughly +3.3, and it nearly doubles your chance of rolling a natural 20, from 5% to 9.75%. Disadvantage (keep the lower) mirrors this, dropping the average to about 7.18.
Are Virtual Dice Fair?
Virtual dice are typically fairer than physical ones. Each roll uses a pseudorandom number generator that gives every face an exactly equal probability, then produces each roll independently of the last.
Physical dice, by contrast, carry real imperfections: air bubbles in cheap molded dice shift the center of mass, rounded edges wear unevenly over time, and studies of mass-produced dice have measured face biases of a few percent. Casino dice are machined to tolerances of a fraction of a millimeter precisely because ordinary dice are not truly fair.
What virtual dice cannot fix is the gambler’s fallacy. Three natural 1s in a row does not make a 20 more likely next roll — every throw is independent, and streaks are a normal feature of genuine randomness, not evidence of a broken roller.
Frequently Asked Questions
Are online dice rollers really random?
Yes, for all gaming purposes. Each roll comes from a pseudorandom number generator that gives every face an equal chance and makes each roll independent of the previous one. The results are statistically indistinguishable from a fair physical die — and often fairer, since manufactured dice carry small physical biases from molding and wear.
How do I roll a d100 with two d10s?
Roll one d10 as the tens digit and another as the ones digit: a 7 and a 3 read as 73. A roll of 0 and 0 counts as 100. Many dice sets include a percentile die marked 00–90 to make the tens digit unambiguous. A virtual d100 skips the decoding and gives you the 1–100 result directly.
What are the odds of rolling a natural 20?
On a single d20, exactly 5% — one face in twenty. With advantage (roll two d20s, keep the higher), the chance of at least one 20 rises to 9.75%. Over a typical game session of 30 d20 rolls, you can expect at least one natural 20 about 79% of the time, so the occasional dry session is normal.
Why is 7 the most common roll on two dice?
Because more combinations add to 7 than to any other total: 1+6, 2+5, 3+4, 4+3, 5+2, and 6+1 — six of the 36 equally likely outcomes, or 16.7%. Totals get rarer toward the extremes; 2 and 12 each have only one combination (2.8%). This triangular distribution is why 7 is central to craps and Catan.
What does 3d6+2 mean?
It is standard dice notation: roll three six-sided dice, add the results together, then add 2. The "N" before the d is the number of dice, the number after is the sides, and the modifier adjusts the total. So 3d6+2 produces results from 5 to 20, with totals near the average of 12.5 most likely.