Roll a d10

Percentile

Two d10s, and the double zero everyone argues about

Nominate one die as the tens before you roll, not after. Read it as a multiple of ten, add the units die, and you have a number from 1 to 100. Every reading is obvious except one.

Double zero is 100, not 0. There is no zero on a percentile roll, so the only sensible reading for the lowest pair of faces is the highest result. Want to skip the pairing entirely? The d100 roller rolls it as a single die.

Totals

Range and average, one die to eight

A single d10 averages 5.5, and every die you add moves the average by the same amount while tightening the spread. One eldritch blast beam is a coin toss. Four of them land near 22 most nights.

In play

What actually calls for a d10

The polearm damage die, the hit die for the three durable martial classes, and half of every percentile roll a table makes.

Fighter, paladin and ranger hit die

1d10

Heavy crossbow, glaive, halberd, pike

1d10

Longsword or battleaxe, used two-handed

1d10

Eldritch blast, per beam

1d10

Paired with a second d10 for percentile

d100

Most percentile rolls at a D&D table are looking something up. The wild magic surge table is the one that comes up most.

Questions

How do you roll a d100 with two d10s?

Pick one die as the tens and one as the units before you roll, then read the tens die as a multiple of ten and add the units. A 70 and a 3 is 73. The one case people get wrong is a double zero, which reads as 100, not 0. Percentile sets usually have one die marked 00 through 90 to make the pairing obvious.

Which classes use a d10 hit die?

Fighters, paladins and rangers. It sits between the d8 that most classes use and the d12 that only barbarians get, which is roughly where those three sit on the durability scale.

What is the average roll on a d10?

5.5. For several dice, multiply: 2d10 averages 11, 4d10 averages 22, 8d10 averages 44. A warlock firing four eldritch blast beams at level 17 is rolling 4d10, so 22 before any invocations.

Is a d10 numbered 0 to 9 or 1 to 10?

The faces are usually printed 0 through 9, and the 0 is read as 10 when you roll it on its own. The same 0 is read as zero when the die is acting as the units half of a percentile pair. Same die, two jobs, which is where most of the confusion comes from.

What weapons deal 1d10 damage?

The reach and heavy polearms, mostly: glaive, halberd and pike. The heavy crossbow also deals 1d10, as does a longsword, battleaxe or warhammer swung two-handed rather than one.

How many beams does eldritch blast get?

One to start, a second at level 5, a third at level 11 and a fourth at level 17. Each beam is a separate 1d10 and a separate attack roll, which is why agonising blast scales so hard.