A d8 is an eight-sided die numbered 1 to 8, each face equally likely. One roll averages 4.5. Rolling 2d8 + 3 gives a total between 5 and 19 with an average of 12. Set the number of dice and a modifier here and the roller shows every face and the sum.
Tabletop players reach for a d8 for longsword and warhammer damage, cleric and rogue hit dice, and many spell effects. When the physical die has rolled under the sofa, or a hit needs six of them at once, this roller does the arithmetic. Choose how many d8 to throw, an optional flat modifier, and how many of the lowest dice to discard. The result lists each die's face, marks the ones dropped, and gives the range and long-run average for that roll. Faces come from your browser's random number source, so outcomes are fair but cannot be replayed or audited like a die rolled at the table in front of other players.
Use the − and + buttons to roll between 1 and 20 d8 together.
Type a bonus or penalty such as 3 or -2; it is applied to the sum of the kept dice.
Raise Drop lowest dice to discard the smallest faces, as in 4d8 drop 1.
The table lists each die, its face and whether it counted toward the total.
Result Total: 6
Roll: 1d8
Lowest possible: 1
Highest possible: 8
Average total: 4.5
A single eight-sided die lands on 1 to 8 with equal chance, averaging 4.5 over many rolls.
Result Total: 12
Roll: 2d8+3
Lowest possible: 5
Highest possible: 19
Average total: 12
Two d8 plus a +3 bonus can total anywhere from 5 to 19 and average 12.
Result Total: 11
Roll: 4d8 drop 1
Lowest possible: 3
Highest possible: 24
Average total: Above 13.5
Four dice are rolled and the smallest is set aside, so three dice count toward the total.
total = sum of kept faces + modifier; average = dice × 4.5 + modifier
facedicemodifierEach die is drawn independently and uniformly from 1 to 8. The mean of one die is (1 + 8) ÷ 2 = 4.5, and by linearity of expectation the mean of several dice is that figure times the count. The lowest possible total is one per kept die plus the modifier; the highest is eight per kept die plus the modifier. When dice are dropped the average shifts upward, so the tool reports it only as a lower bound.
The average is 4.5, the midpoint of 1 and 8. Over many rolls each face appears about one time in eight, so the mean settles near 4.5. Two d8 average 9, three average 13.5.
Roll two eight-sided dice, add their faces together, then add 3. The total ranges from 5 to 19, and 12 is the average result.
In Dungeons & Dragons fifth edition the d8 is the damage die for longswords, rapiers and warhammers, and the hit die for clerics, rogues, bards, druids and monks. Many other tabletop systems use it for weapon damage too.
Yes. Each die picks a whole number from 1 to 8 with equal weight using the browser's random source, so no face is favoured, unlike a cheap physical die with uneven pips or edges.
Discarding the lowest faces pushes the expected sum above the plain average of the kept dice. Working out the exact figure needs order statistics, so the tool shows the simple average as a floor rather than an exact value.
Under the fifth-edition rule you double the damage dice, not the modifier. A longsword critical becomes 2d8 plus your bonus, so set the dice count to 2 and keep the modifier unchanged.
Using this tool in an assignment, article or report? Copy a citation, or a link for your website.
Tools Directory Editorial Team. (2026, October 14). D8 Roller. Tools Directory. Retrieved October 26, 2026, from https://tools.milunir.com/fun-random/pickers-wheels-and-dice/d8-roller/
Tools Directory Editorial Team. “D8 Roller.” Tools Directory, 14 Oct. 2026, https://tools.milunir.com/fun-random/pickers-wheels-and-dice/d8-roller/. Accessed 26 Oct. 2026.
Tools Directory Editorial Team. “D8 Roller.” Tools Directory. Last modified October 14, 2026. Accessed October 26, 2026. https://tools.milunir.com/fun-random/pickers-wheels-and-dice/d8-roller/.
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