A critical hit in D&D 5e happens when you roll a natural 20 on an attack roll. That attack hits no matter what, and you roll all of its damage dice twice and add them together, then add your modifiers once. That’s the whole core rule. The rest of this guide covers the fine print (Sneak Attack, spells, death saves), the real odds, how older editions did it, and the house rules tables use to make a 20 feel like a small religious experience.
Grab your favorite d20. Yes, that one. The one you’ve been quietly blaming for three sessions.
TL;DR
- A natural 20 on an attack roll is an automatic hit and a critical hit. You roll the attack’s damage dice twice and add your flat modifiers once.
- The base chance is 5%. Advantage pushes it to about 9.8%, and a Champion Fighter’s expanded range pushes it to 10% or 15% before advantage.
- Spells only crit if they use an attack roll. Saving throw spells never do.
- Popular house rules include max damage plus a roll, exploding dice and fumble tables. Agree on them at session zero, not mid-fight.
- A good crit deserves a good die. Skip to the dice section if you’re shopping.
Table of Contents
- What a critical hit actually is
- How critical hit damage works
- What are the odds of a critical hit?
- Do spells and special attacks crit?
- Critical hits across editions
- Popular house rules for critical hits
- Perspective
- Dice for your next natural 20
- Tips for running crits at your table
- Common mistakes with critical hit rules
- FAQ
What a critical hit actually is
When you roll a 20 on the die during an attack roll, it’s a critical hit and you deal extra damage, according to the 2022 D&D Quick Reference from Wizards of the Coast. The 5th Edition SRD adds the important part: a natural 20 hits regardless of modifiers or the target’s Armor Class. So the goblin’s fancy plate armor and the dragon’s AC 19 both politely step aside.
“Natural” means the number showing on the die, before any bonus. A 17 plus a +3 is a 20 on paper, but it’s not a crit. It’s just a very good Tuesday.
The flip side is the natural 1, which automatically misses whatever your modifiers. Notice what the rule doesn’t say: nothing about dropping your sword, hitting the cleric, or your bowstring snapping. A 1 is a miss. Any extra drama is a house rule, and we’ll get there.
How critical hit damage works
Here’s the sequence at the table:
- Roll your attack. The die shows a 20.
- Announce it with the appropriate volume. (Mandatory. Neighbors have been warned.)
- Roll all of the attack’s damage dice twice and add them together, per the SRD’s damage rules.
- Add your modifiers once.
That last step trips people up all the time. A critical hit does not double flat modifiers like your Strength or Dexterity bonus. Only the dice get doubled.
A worked example
Say your fighter swings a greatsword (2d6) with a +4 Strength modifier.
| Attack | Dice rolled | Average dice total | Modifier | Average damage |
|---|---|---|---|---|
| Normal hit | 2d6 | 7 | +4 | 11 |
| Critical hit | 4d6 | 14 | +4 | 18 |
So a crit takes you from an average of 11 to an average of 18. That’s a big swing, but you didn’t double the +4, and you shouldn’t. Your DM is not cheating you, and you’re not cheating the DM. The math is just the math.
Sneak Attack and other extra dice
Extra dice attached to the attack count too. Under the 2024 rules, additional damage dice such as Sneak Attack are also rolled twice on a critical hit, while damage modifiers still aren’t doubled. A rogue who crits with 5d6 of Sneak Attack is suddenly rolling a very large handful of d6s.
Which is a fine time to mention that a rogue with a fistful of d6s is a happy rogue. If that’s your player (or you), a 10d6 dice set saves the endless “wait, which six was that one?” shuffle. Our Heart of Shadows rose and black resin 10d6 set is built for exactly this kind of dice-pile moment.
Crits against a creature at 0 hit points
This one is grim, so use it wisely. Damage from a critical hit can cause instant death or multiple failed death saving throws when a creature is already at 0 hit points. If you’re a player, this is why your DM suddenly gets quiet when a downed party member is next to an enemy. If you’re a DM, it’s a tool, not a gotcha.
What are the odds of a critical hit?
For a single ordinary attack, the chance of a crit is 5%, or 1 in 20. With advantage, it rises to about 9.8% because you get two chances to roll a 20. With disadvantage, you need both dice to show 20, which works out to 1 in 400, or 0.25%. At that point your d20 isn’t unlucky. It’s under a curse.
| Situation | Crit range | Chance per attack |
|---|---|---|
| Normal attack | 20 | 5% |
| Advantage | 20 | about 9.8% |
| Disadvantage | 20 | 0.25% |
| Expanded range (19-20) | 19-20 | 10% |
| Expanded range (18-20) | 18-20 | 15% |
The 19-20 and 18-20 ranges come from the Champion Fighter. In the 2024 rules, the subclass’s Improved Critical feature expands the critical range to 19 or 20, and Superior Critical later widens it to 18-20. Those ranges apply to weapon attacks and Unarmed Strikes.
Advantage stacks nicely with that. At a 19-20 range, you have a 10% chance per die, so rolling two dice gives you a 1 in 5 shot at a crit, about 19%, by simple probability. Designers have noted that expanded ranges grow more influential alongside advantage and multiple attacks, since every extra d20 is another chance to land in the range. Your DM may squint at your Champion with Reckless Attack. That squint is earned.
How to increase your chance of a crit
There’s no secret trick, just a short list:
- Take a subclass or feature that widens the crit range, like the Champion.
- Get advantage as often as you can: flanking-style tactics (if your table uses them), Reckless Attack, hiding, and spells or abilities that grant it.
- Make more attacks. More d20s means more shots at a 20.
What doesn’t work: blowing on the die, rolling in a special tray, or promising it a treat. We’ve tested all three. Our dice remain unmoved. (We do think a pretty die feels luckier, though. Science has not weighed in.)
Do spells and special attacks crit?
It depends on how the spell resolves. In 5e, a spell with an attack roll can score a critical hit if it rolls a natural 20. A spell that makes the target roll a saving throw does not crit, per this breakdown of the rules. So a ranged spell attack like Fire Bolt can crit, while Fireball just does its thing.
Same source, same logic for classes: Sneak Attack dice double on a crit, and saving throw spells never do.
This is the one question new players ask more than any other, so here it is in plain terms. If you roll a d20 to see whether you hit, a 20 is a crit. If the target rolls to see whether they dodge, no crit.
Critical hits across editions
If your group has a veteran who keeps saying “back in my day,” they’re not wrong. Crits have changed.
- 3.5e: A natural 20 was only a threat. You needed a second attack roll that also hit the target’s AC to confirm it. Spells that required an attack roll could crit, and spells with no attack roll could not.
- 5e: No confirmation roll. A natural 20 is a crit, full stop.
- Older editions: The natural 20 as an optional critical hit rule first appeared in published D&D in the AD&D 2nd Edition Dungeon Master’s Guide, according to a community discussion on the history. The same thread notes that first edition actively warned against crit systems, worried they’d shorten player character life expectancy. Cheerful bunch.
So when someone at your table says “you have to confirm it,” check which edition they’re remembering. Then check whether they also remember to bring snacks.
Popular house rules for critical hits
The official crit is perfectly fine, but it has a known quirk: you can roll a crit and still get a low damage roll. Nothing flattens a table like a natural 20 followed by a total of 6. Here are the common fixes, from least to most chaotic.
Max damage plus a roll
The attacker takes the maximum value of the damage dice, then rolls the normal damage and adds it. Using our greatsword: 12 (max of 2d6) plus a normal 2d6 roll, plus 4. That averages 23, versus 18 under the official rule. One popular thread on this approach notes it adds roughly three points of average damage per die compared to simply doubling dice, though the exact gain depends on the die size. Check the numbers for your own weapons before you promise players the moon.
The upside: no more sad crits. The downside is it makes crits against you hit harder too, and that includes monsters. You’ve been warned, and so has your wizard.
Exploding dice
When a damage die shows its maximum value, you roll it again and add the result, possibly forever. These “exploding” variants let dice be re-rolled when they show maximum, which creates spiky, dramatic damage. Related variants add a die each time maximum damage is rolled, or add dice once after a maximum-damage roll.
It’s thrilling. It’s also how a goblin occasionally one-shots a paladin. Pick this if your table likes chaos with their snacks.
Maximum damage on a 20
Some DMs treat a natural 20 as an automatic hit that deals maximum possible damage instead of rolling extra dice. Older musings on house rules describe this style. It’s fast and removes the “my crit rolled a 2” feeling, though you lose the fun of rolling a big pile of dice. Which is, frankly, half the point.
Fumbles on a natural 1
Some tables add critical failure rules, often triggering a mishap or a free enemy attack on a natural 1. That is not part of standard 5e, where a 1 just misses. If you want it, here are a few guidelines:
- Tell players before the campaign starts.
- Apply it to monsters too. Fair is fair.
- Keep consequences small and funny, not punishing. A dropped torch is fun. A lost arm is a different campaign.
Fumble rules multiply fast when characters make many attacks per turn, so many DMs skip them for high-level fighters.
Which house rule should you pick?
| If your table wants… | Try |
|---|---|
| Faster, safer play | Official rules, no changes |
| Crits that always feel big | Max damage plus a roll |
| Wild, story-making swings | Exploding dice |
| Less math at the table | Max damage on a 20 |
| Drama on both sides | Fumble table, used lightly |
Whatever you pick, agree on it at session zero, write it down, and apply it to the monsters. Nothing builds resentment like a house rule that only helps the DM.
Perspective
We’ve watched a lot of tables go quiet for half a second after someone calls a natural 20. That pause is the best part of the game. Everyone’s eyes go to the die, and for that moment the whole table is rooting for one person.
That’s why we care about the dice themselves. The rules decide what a crit does, but the die decides how it feels. A liquid core die with a little glimmer rolling across the table, or a heavy metal die landing with a clack, turns a 5% event into a story people retell for years.
We build our sets for players who want that moment to look as good as it feels, and we think the collective around the game matters just as much as the game. So whether you’re a stern rules lawyer or a gleeful exploding-dice chaos goblin, pick the rules that make your table cheer, then pick a die worthy of them.
Teresa
Dice for your next natural 20
If you want to know which die does what, our guide to the function of each die in a D&D set breaks it down. Spoiler: the d20 is the one that makes your heart do a little jump.
Ready to upgrade the die that decides your crits? Browse our full range of DnD dice, from metal and resin to wood. For a die that looks like it’s concentrating, try the liquid core collection. For something that looks like a treasure hoard, our gemstone dice sets are worth a look.
Can’t choose? Our Mystery Luxury Bundle packs in standard sets plus an RPG accessory, and you get a surprise. Buying for someone else? Our gift picks for RPG and tabletop gamers are a solid start. And if you’re still building a kit, our guide to the best dice for tabletop RPG campaigns and player accessories worth buying will help you shop without regrets. Our Swashbuckler 14-piece set is a nice option if you want a spare set for the party’s chaos agent.
Tips for running crits at your table
Describe the hit. A crit is a narrative gift. “You hit for 18” is fine. “Your blade slips between the plates and the ogre’s eyes go wide” is better. Let players narrate their own crits when you can.
Remember who’s rolling. If crits work on monsters too, say so before combat. Players handle a goblin crit much better when they know it’s coming from the same rulebook as theirs.
Count your dice before rolling. Count the damage dice, double them, grab them all at once. It saves the “wait, was that two dice or four?” moment.
Keep a crit die on the table. Some players keep a special d20 for attacks only. It’s superstition, and superstition is allowed here.
Don’t overthink it. Crits are supposed to be fun. If a rule slows the game, change it.
Common mistakes with critical hit rules
- Doubling the modifier. Only the dice double. Your +4 stays +4.
- Treating a 20 plus modifiers as a crit. The natural die roll counts, not the total.
- Letting saving throw spells crit. They don’t, as the rules breakdown notes.
- Forgetting extra dice. Sneak Attack and similar dice double, per the 2024 rules.
- Assuming a natural 1 is a disaster. By the official rules, it’s just a miss.
FAQ
What is a critical hit in Dungeons and Dragons?
It’s what happens when you roll a natural 20 on an attack roll. The attack hits automatically, and you roll its damage dice twice, adding your modifiers once. It’s the game’s way of rewarding a lucky swing.
What is the chance of landing a critical hit?
On a normal attack it’s 5%, or 1 in 20. With advantage it’s about 9.8%. Expanded ranges like the Champion’s 19-20 raise the base chance to 10%, and 18-20 raises it to 15%.
Do critical hits ignore attack drops, like penalties to the roll?
A natural 20 hits regardless of modifiers or the target’s AC, so penalties to the total don’t matter. Disadvantage does affect it, since you roll two dice and use the lower one, leaving a 0.25% chance. A penalty to the roll itself won’t stop a natural 20.
How do I increase the chance of a critical hit?
Get advantage as often as you can, make more attacks, or pick a feature that expands your crit range, such as the Champion Fighter. Each of those gives you more d20s or a bigger target range.
Can spells score critical hits?
Yes, if the spell uses an attack roll. Spells that force a saving throw don’t crit. So Fire Bolt can, and Fireball can’t.
