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8d6 Dice Probability — Full Distribution and Odds

Eight dice is where the standard deviation stops mattering much: almost every roll lands within about 4 of 28. The sum runs from 8 to 48, the average is 28, and the most likely total is 28. Below is every sum with its exact number of ways, its probability, the cumulative odds and the "at least" thresholds worth memorising.

Range8 – 481,679,616 outcomes
Average28σ = 4.83
Most likely288.09%

Every possible sum

SumWaysExactlyAt mostAt leastOdds of exactly
810.000%0.000%100.0%1 in 1679616
980.000%0.001%100.0%1 in 209952
10360.002%0.003%100.0%1 in 46656
111200.007%0.010%100.0%1 in 13997
123300.020%0.029%100.0%1 in 5090
137920.047%0.077%100.0%1 in 2121
141,7080.102%0.178%99.9%1 in 983
153,3680.201%0.379%99.8%1 in 499
166,1470.366%0.745%99.6%1 in 273
1710,4800.624%1.37%99.3%1 in 160
1816,8081.00%2.37%98.6%1 in 99.9
1925,4881.52%3.89%97.6%1 in 65.9
2036,6882.18%6.07%96.1%1 in 45.8
2150,2882.99%9.07%93.9%1 in 33.4
2265,8083.92%13.0%90.9%1 in 25.5
2382,3844.90%17.9%87.0%1 in 20.4
2498,8135.88%23.8%82.1%1 in 17
25113,6886.77%30.5%76.2%1 in 14.8
26125,5887.48%38.0%69.5%1 in 13.4
27133,2887.94%46.0%62.0%1 in 12.6
28135,9548.09%54.0%54.0%1 in 12.4
29133,2887.94%62.0%46.0%1 in 12.6
30125,5887.48%69.5%38.0%1 in 13.4
31113,6886.77%76.2%30.5%1 in 14.8
3298,8135.88%82.1%23.8%1 in 17
3382,3844.90%87.0%17.9%1 in 20.4
3465,8083.92%90.9%13.0%1 in 25.5
3550,2882.99%93.9%9.07%1 in 33.4
3636,6882.18%96.1%6.07%1 in 45.8
3725,4881.52%97.6%3.89%1 in 65.9
3816,8081.00%98.6%2.37%1 in 99.9
3910,4800.624%99.3%1.37%1 in 160
406,1470.366%99.6%0.745%1 in 273
413,3680.201%99.8%0.379%1 in 499
421,7080.102%99.9%0.178%1 in 983
437920.047%100.0%0.077%1 in 2121
443300.020%100.0%0.029%1 in 5090
451200.007%100.0%0.010%1 in 13997
46360.002%100.0%0.003%1 in 46656
4780.000%100.0%0.001%1 in 209952
4810.000%100.0%0.000%1 in 1679616

Rolling a target or higher

This is the form most checks actually use — "did I beat 12?" rather than "did I roll exactly 12".

TargetChance of meeting itOdds
≥ 2387.0%1 in 1.15
≥ 2669.5%1 in 1.44
≥ 2946.0%1 in 2.18
≥ 3223.8%1 in 4.21
≥ 359.07%1 in 11

Reading the shape

Each die is uniform, but the sum is not. 8d6 has 1,679,616 ordered outcomes spread over 41 totals, and the counts rise toward the middle because a middle total can be assembled from more orderings. The curve is symmetric around 28 — for every way to roll 27 there is a mirrored way to roll 29 — which is why the standard deviation of 4.83 describes the spread on both sides equally.

Compare that with a single die: 1d6 is a flat line at 16.7% per face. Adding dice does not widen the range proportionally — it makes extreme results rarer. That is the whole reason systems that want predictable outcomes roll pools, and systems that want drama roll one big die.

Frequently asked

What is the average roll of 8d6?
28. The formula is dice × (faces + 1) / 2 — 8 × (6 + 1) / 2 — which works for any fair die. The standard deviation is 4.83, so most rolls land between 23 and 33.

What is the most likely total on 8d6?
Exactly 28, at 8.09% — 135,954 of the 1,679,616 equally likely outcomes. The extremes (8 and 48) take 1 way each, or 0.000%.

How many possible outcomes does 8d6 have?
1,679,616 ordered outcomes — 68 — collapsing into 41 possible sums from 8 to 48. The counts here are exact integers from a convolution, not a normal approximation, so the tails are right: a normal curve would misstate the odds of the extreme rolls.

Why is the middle so much more likely than the ends?
Because sums have more ways to happen than faces do. There is exactly one way to roll all ones, but a middle total can be assembled from many orderings, and each ordering is a distinct outcome. That is why 8d6 has a single peak at 28 and why adding dice makes the distribution tighter rather than wider.

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