Roll a d10

The odds on a d10

A single die is flat: no total is more likely than any other. The curve only appears once you roll more than one, which is what the 2d10 page is for.

Lowest

1

Highest

10

Average

5.50

Each face

10.0%

Odds

1 in 10

Every bar the same height. That flatness is the whole point of a single die: 10.0% per face, no favourites.

What a d10 is for

Heavy crossbow and pike damage, percentile rolls in pairs, and sorcerer hit dice.

Hitting a target number

What a flat d10 beats, and how much two-dice advantage moves it.

How to use this roller

Tap the die or press the roll button. To roll several at once, change How many. To add a bonus, put it in Modifier: entering 3 turns a d10 into 1d10+3. Negative numbers work for penalties. The keyboard shortcut is R.

Nothing is stored on a server and no account is needed. The page works offline once loaded, which matters if the venue has poor signal.

Common questions about the d10

What are the odds of rolling a 10 on a d10?

Exactly 10.0%, or 1 in 10. Every face on a fair d10 is equally likely, so a 10 is no rarer than a 7.

What is the average roll on a d10?

5.5. That is the midpoint of 1 and 10, and it is worth knowing because the average of a die is always (sides + 1) divided by 2. Over many rolls your results converge on it, but any single roll tells you nothing.

Does rolling with advantage change the odds of a 10?

Advantage is a d20 mechanic, but the maths applies to any die. Rolling two d10 and keeping the higher would raise your chance of a 10 from 10.0% to 19.0%.

Is this d10 roller actually random?

Every roll comes from the Web Crypto API rather than Math.random, and uses rejection sampling to discard values that would skew the result. A plain modulo of a random number is biased when the range does not divide evenly, which for a d10 would quietly favour the low faces.

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