Roll two dice online with adjustable sides, modifiers, drop highest/lowest, and target checks. Full sum distribution and doubles tracking included.
Rolling two dice is perhaps the most fundamental random event in tabletop gaming. From Monopoly and Settlers of Catan to craps and backgammon, the humble pair of dice creates a bell-shaped probability distribution that rewards middle values and makes extreme outcomes rare. Understanding how two-dice sums work is a gateway to probability and statistics.
Our 2 Dice Roller lets you throw any pair of same-sided dice — not just the classic d6 — with optional modifiers, advantage/disadvantage mechanics, and target checks. Whether you're simulating board game turns, running tabletop RPG encounters, or exploring probability, this tool provides instant results with full statistical analysis.
Every roll is tracked in a history table with doubles highlighted, and a live sum distribution chart shows you how your observed results compare to theoretical expectations. It's the perfect companion for game night or a statistics classroom, especially when you want to connect actual rolls to the triangular 2d6 distribution.
Physical dice can roll off the table, show ambiguous results, or slow down gameplay. Our digital roller delivers instant, unambiguous results and keeps a full history so you never lose track. The built-in distribution chart turns every game session into a mini probability lesson.
For game designers and statisticians, the ability to switch die sizes, test advantage mechanics, and run hundreds of rolls at once makes this tool invaluable for balancing encounters, testing house rules, or just satisfying curiosity about two-dice probability.
For 2dN: possible sums range from 2 to 2N. Expected value: E = N + 1. Probability of doubles: P = 1/N. Number of distinct sums: 2N - 1. Probability of sum S: P(S) = (N - |S - (N+1)|) / N².
Result: 2d6 → [3, 5] → Total = 8
Rolling two standard 6-sided dice produced 3 and 5. The sum is 8, which is above the expected value of 7. With 2d6, 8 has a 5/36 (13.9%) probability.
When you roll two fair N-sided dice, the sum follows a discrete triangular distribution. For the classic 2d6 case, there are 36 equally likely outcomes (6 × 6). The sum of 7 appears most often because six different pairs produce it — more than any other sum. The probabilities decrease symmetrically as you move away from 7 toward the extremes of 2 and 12.
This triangular shape has profound implications for game design. In Settlers of Catan, resource tiles are numbered 2-12, with tiles near 7 being the most productive. Craps betting odds directly reflect these probabilities.
A common game design question is: should I use 2d6 or 1d12? Both cover similar ranges, but they behave very differently. One d12 gives every number (1-12) equal probability. Two d6 strongly favor middle values and rarely produce extremes. This makes 2d6 systems more predictable — skilled characters succeed more consistently because outlier rolls are suppressed. Systems that want dramatic swings prefer single-die resolution.
Rolling two dice and keeping the best (or worst) is a powerful probability modifier used in many modern RPGs, most famously D&D 5th Edition's advantage/disadvantage system. Keeping the higher of 2d20 shifts the average from 10.5 to about 13.8 — roughly equivalent to a +3.3 bonus — but with a non-linear boost that helps more on moderate DCs than extreme ones.
The most common sum is 7, appearing with probability 6/36 ≈ 16.7%. There are six combinations that make 7: (1,6), (2,5), (3,4), (4,3), (5,2), (6,1).
With two N-sided dice, the probability of doubles is 1/N. For 2d6, that's 1/6 ≈ 16.7%. For 2d20, it's 1/20 = 5%.
You roll both dice but only keep the higher result. This shifts the average upward and is often called "advantage" in RPG systems.
Yes! Set sides to 6, no modifier, keep both dice. In craps, 7 and 11 win on the come-out roll; 2, 3, or 12 lose; anything else sets a point.
Each sum has a different number of dice combinations that produce it. Sum 7 has 6 ways, sum 2 and 12 have only 1 way each, creating a triangular (not uniform) shape.
The variance of one d6 is 35/12 ≈ 2.917. For two independent d6s, variance doubles to 70/12 ≈ 5.833, giving a standard deviation of ~2.415.