Short answer
The d20 decides whether you succeed. The other dice (d4, d6, d8, d10 and d12) decide how much: how much damage you deal, how many hit points you heal. The percentile pair of d10s makes a d100 for random tables. One standard set of seven dice is enough to play.
Each die and its job
| Die | Sides | Main job | Examples in the 2024 rules |
|---|---|---|---|
| d4 | 4 | Small weapons, small heals, small bonuses | Dagger damage, each Magic Missile dart (1d4 + 1), Healing Word (2d4 + modifier), a Potion of Healing (2d4 + 2) |
| d6 | 6 | The workhorse damage die | Shortsword, Fireball (8d6), Sneak Attack, Hunter's Mark, Wizard and Sorcerer hit dice |
| d8 | 8 | Mid-size weapons and heals | Longsword, rapier, longbow, Cure Wounds (2d8 + modifier), Rogue and Warlock hit dice |
| d10 | 10 | Heavy weapons and strong cantrips | Heavy crossbow, Fire Bolt, Eldritch Blast, Fighter, Paladin and Ranger hit dice |
| d12 | 12 | The biggest single hit | Greataxe, the Barbarian hit die |
| d20 | 20 | Every D20 Test: attacks, ability checks, saving throws | Initiative, Stealth checks, death saving throws |
| d100 | Two d10s | Percentile tables | Random trinkets, the Teleport outcome table, some magic item effects |
A quick rule of thumb from running games: the bigger the die, the bigger the weapon or the tougher the class. Wizards roll a d6 for hit points. Barbarians roll a d12. The same pattern shows up in weapons. A dagger is a d4 and a greataxe is a d12.
The d4
The pyramid. It doesn't roll so much as land, and the number you read is usually at the top point or along the bottom edge, depending on the set. It's also the one that hurts when you step on it.
The d6
The same cube as in any board game. It's the die you'll roll in the biggest piles. A level 5 rogue adds 3d6 Sneak Attack, and a Fireball is 8d6.
The d8, d10 and d12
The middle dice cover most weapons and most heals. The d10 is the one people mix up with the percentile die: a regular d10 reads 0 to 9 (count the 0 as 10), while the percentile die reads 00, 10, 20 and so on.
The d20 and D20 Tests
The 2024 rules call the three main rolls D20 Tests: ability checks, saving throws and attack rolls. Each works the same way. Roll the d20, add the modifier from your sheet, and compare the total to a target number. For a check or a save, that's the Difficulty Class (DC) the DM sets. For an attack, it's the target's Armor Class (AC). Meet or beat it and you succeed.
Two more d20 rolls you'll see often: initiative, which is a Dexterity check rolled at the start of combat to set turn order, and the death saving throw, rolled when you start your turn at 0 hit points. A 10 or higher is a success. Three successes and you're stable. Three failures and your character dies.
Advantage and Disadvantage
- Advantage: roll two d20s and keep the higher one. You get it from things like attacking a target that can't see you, or from a helpful spell.
- Disadvantage: roll two d20s and keep the lower one. You get it from things like attacking while Poisoned or shooting at long range.
- They don't stack. Three sources of Advantage still means only two dice.
- They cancel. If you have both, you have neither and roll one d20, even if one side has more sources than the other.
Advantage is worth more than it sounds. On a roll where you need an 11, it lifts your chance of success from 50% to 75%. Disadvantage drops that same roll to 25%.
Criticals and natural 1s
A "natural" roll is the number on the die before any modifiers.
| Roll | Attack roll | Death saving throw | Ability check or save |
|---|---|---|---|
| Natural 20 | Hits no matter the AC. It's a Critical Hit: roll all the attack's damage dice twice, then add modifiers once | You regain 1 hit point and get back up | No special effect in the rules. Just add your modifier as normal |
| Natural 1 | Misses no matter what you add | Counts as two failures | No special effect in the rules |
Extra dice count too. A rogue who crits with a dagger at level 5 rolls 2d4 for the dagger and 6d6 for Sneak Attack. Many tables play that a 20 on a skill check always succeeds. That's a house rule, not the 2024 rules, so ask your DM.
Rolling d100
Roll the percentile die (marked 00 to 90) and a regular d10 together, then add them. A 40 and a 7 is 47. A 00 and a 0 is 100. The rules use d100 for random tables. The free System Reference Document's trinket table and the Teleport spell's outcome table are two examples. If you don't have a percentile die, roll one d10 twice: tens first, then ones.
Reading dice notation
| You see | It means |
|---|---|
| 1d8 | Roll one eight-sided die |
| 2d6 + 3 | Roll two six-sided dice, add them, then add 3 |
| 8d6 | Roll eight d6 and add them all (a Fireball) |
| 1d20 + 5 | A D20 Test with a +5 modifier |
| 1d100 | A percentile roll using two d10s |
Some adventures ask for a d2 or d3. Neither exists in a standard set. Flip a coin for a d2, or roll a d6 and halve it, rounding up, for a d3.
How many dice to buy
One standard set of seven (d4, d6, d8, two d10s, d12, d20) is all you need for a first game. Most starter sets come with one. After that, buy for your class:
- Rogue: extra d6s. Sneak Attack reaches 10d6, and rolling them all at once saves the table time.
- Wizard or Sorcerer: eight to ten d6s for Fireball and similar spells.
- Anyone: a second d20 makes rolling with Advantage faster.
- The DM: two or three full sets, so monsters can roll without hunting for the right die.
Pick dice you can read at a glance. Sparkly dice with low-contrast numbers look great on the shelf and slow down every roll.
Questions
Do I need my own dice?
Not for a first game. Groups often share. Most players buy a set within a few sessions, because rolling your own dice is part of the fun.
Can I use a dice app instead?
Yes. Apps and virtual tabletops roll the same odds. Ask the DM first if you're playing in person, since some tables prefer physical dice.
Corin Ashdown is the pen name of the editor who writes and checks every guide on Vorbelutrioperbir. How we write and check guides.