Dice Roller D&D 5e — Roll Any Dice in Seconds

How dice work in D&D 5e

The seven dice

A 5e dice set has d4, d6, d8, d10, d12, d20 and d100. The d20 resolves nearly everything that is uncertain: attacks, saving throws, ability checks. The other dice set amounts, damage, hit points and spells. A d100 sits on top of a d10 and is used for wild magic, treasure rolls and random tables.

The three ways to roll ability scores

Standard array gives you 15, 14, 13, 12, 10, 8 to place as you like. Point buy hands you 27 points and lets you trade them for a spread that suits your class. Rolling — the method most tables start with — is four six-sided dice keeping the best three, six times. Each method has a different risk profile: rolling can beat the standard array outright, and it can also leave you with a flat 8 in your main stat.

Why "4d6 drop lowest" is not the same as "4d6"

Plain 4d6 averages 14. Dropping the lowest die pushes the average to about 12.24 but sharply cuts the bad outcomes, because a single 1 no longer drags the whole score down. Only 1.6% of 4d6-drop-lowest results come out under 6, against 1.9% for plain 4d6. That is why the method is popular: it is swingier than point buy but rarely leaves you crippled.

Advantage and disadvantage

Roll two d20 and keep either the higher or the lower one. Advantage raises your average roll from 10.5 to 13.83, which is worth roughly +4 to +5 on the roll that matters. Disadvantage is its mirror image. Neither ever stacks: two sources of advantage are still two dice, not three.

Modifiers and the DC ladder

A DC 5 is easy enough that a competent person rarely fails, 10 is a routine task, 15 is the common "you need to be good at this" line, 20 is hard, 25 very hard and 30 nearly impossible. Add your bonus to the d20 and compare. A natural 20 on an attack always hits and a natural 1 always misses; for ability checks the rules say nothing automatic, but many tables house-rule it anyway. Note that DC 20 against a +5 character is only a 30% chance, which is why most DMs save DC 20 for the moment they want you to fail.

Dice notation, decoded

Every roll in 5e is written as NdX: N dice, each with X sides. The table below covers what the notation actually means in play.

The letters matter. kh and kl keep the highest or lowest result. dh and dl drop it. Add or subtract a flat number last, never before, because keep and drop act on the rolled dice only.

Rolling, standard array or point buy: which to pick

All three are legal, and all three feel different at the table.

• Rolling 4d6 drop lowest produces the most interesting sheet and the most lopsided one. The average is 12.24 per ability, but a main stat of 9 is entirely possible and a DM should think about whether that player will have fun for the next thirty sessions.
• Standard array (15, 14, 13, 12, 10, 8) is the fastest route to a playable character and the fairest at a table of mixed experience levels.
• Point buy gives everyone the same 27 points. It is the method organised play uses, because nobody can arrive with three 17s.

One table rule that fixes most of the complaints about rolling: let players roll two sets of six and pick the better. It keeps the fun of dice and removes the session-long sulk about a character built on an 8.

What advantage is actually worth

Advantage rolls two d20 and keeps the higher. It raises your average roll from 10.5 to 13.83, but the average is the least useful way to look at it, because what changes is the shape of the odds, not just the middle.

The common shorthand that advantage is "about plus five" is a good rule of thumb, not a rule. It is closest to plus five exactly when the roll is a coin flip, and weakest when your chance was already extreme, because the ceiling of 100 percent is doing the work. Advantage never stacks with itself: two sources still means two dice, which matters when a barbarian has reckless attack and the party cleric has cast guidance.

Why 1d12 and 2d6 are not the same

A greataxe deals 1d12 and a greatsword deals 2d6. Both average 7, and both top out at 12, so the greataxe looks like a style choice. It is not quite.

• The greataxe is flat: every result from 1 to 12 has the same 8.3% chance. You can roll a 1.
• The greatsword clusters around the middle: 7 comes up 6 times in 36 chances, while 2 and 12 each come up once. You cannot roll a 1 at all.

The result is that the greataxe has slightly more upside and much more downside, which matters on a great-weapon fighting character where a low roll triggers a reroll anyway, and on a barbarian whose brutal critical multiplies extra dice. The average is identical; the variance is not. This is why the damage calculator here shows min, average and max side by side instead of just the average.

Average damage, and why it matters at the table

Average damage for dice is the number of dice times half the die plus one half, plus any modifier. So 3d8+5 is 3 × 4.5 + 5 = 18.5 per target. It matters for three practical reasons: deciding between two weapons, comparing a spell slot against a cantrip, and designing an encounter where the monster must survive roughly one round of the party's output.

What the average hides is the shape. A fireball averaging 28 damage still rolls a 10 sometimes, and a monster left on 12 hit points after the average says it died is a very common table situation. Roll it and use the result.

Ability modifiers and the odd numbers problem

The modifier is the score minus 10, divided by two and rounded down. A 15 and a 14 both give +2, which is why every optimisation guide tells you to buy even numbers and spend the leftover point somewhere else. Two things worth knowing: a score of 9 still gives −1, and the only honest way to use a half-feat is to take the odd score and let the feat round it up.