Dungeons & Dragons is a game where you say what your character does, the Dungeon Master (DM) says what happens, and a twenty-sided die settles every argument in between. That is the whole engine. Everything else is detail, and this guide gives you only the detail you need for your first night at the table.
The rules here come from the System Reference Document 5.2.1, the free, openly licensed core of the 2024 rules [1]. If your group plays the 2014 rules, almost all of it still holds; the differences are flagged.
What you need
- The free rules. The SRD 5.2.1 is a free PDF [1]. You do not need to buy a book for your first session.
- Dice. The usual set is a d4, d6, d8, d10, d12, d20 and a second d10 for percentages. No dice yet? The 3D roller throws all of them in your browser.
- A character sheet. The rules count paper, printed and digital sheets alike [1]. Our free character sheets do the arithmetic for you.
- A DM and a few players. Snacks are optional in the rules and mandatory in practice.
The one roll that runs the game
Almost every roll is a D20 Test: roll a d20, add a modifier, compare to a target number [1]. There are three kinds.
| Roll | You add | Meet or beat | Used for |
|---|---|---|---|
| Ability check | Ability modifier (+ proficiency if trained) | A Difficulty Class (DC) the DM sets | Climbing, sneaking, persuading, remembering |
| Attack roll | Ability modifier + proficiency | The target's Armor Class (AC) | Hitting things |
| Saving throw | Ability modifier (+ proficiency if trained) | The DC of the spell, trap or poison | Not getting hit by things |
Your proficiency bonus is +2 at level 1 [1].
Natural 20s and natural 1s. On an attack roll, a 20 on the die always hits and is a Critical Hit; a 1 always misses [1]. On an ability check, a natural 20 is just a 20. Plenty of tables play it as an automatic success anyway. Ask before you try to persuade the king to abdicate.
How good are your odds?
The chance of meeting a DC, worked out from the d20's twenty faces (5% each). Advantage means you roll two d20s and keep the higher [1]; more in our advantage guide.
| Your modifier | DC 10 (easy) | DC 15 (medium) | DC 20 (hard) | DC 15 with Advantage |
|---|---|---|---|---|
| +0 | 55% | 30% | 5% | 51% |
| +2 | 65% | 40% | 15% | 64% |
| +3 | 70% | 45% | 20% | 70% |
| +5 | 80% | 55% | 30% | 80% |
Two things jump out. A +5 against a hard DC still fails 70% of the time, so "hard" means hard. And Advantage is worth about +4 or +5 in the middle of the die, which is why every rogue you ever meet is scheming for it.
The six abilities
| Ability | What it covers | Who lives on it |
|---|---|---|
| Strength | Lifting, shoving, hitting with heavy weapons | Barbarian, Fighter, Paladin |
| Dexterity | Aim, balance, reflexes, stealth | Rogue, Monk, Ranger |
| Constitution | Hit points, staying conscious, holding a spell | Everyone, quietly |
| Intelligence | Memory, reasoning, research | Wizard |
| Wisdom | Perception, insight, instinct | Cleric, Druid |
| Charisma | Force of personality | Bard, Sorcerer, Warlock, Paladin |
Making your first character
The SRD's order: class, then origin (background and species), then ability scores, then alignment, then the details [1].
Step 1: Pick a class
The SRD rates every class for complexity [1]. For a first character, start at Low.
| Complexity | Classes |
|---|---|
| Low | Fighter, Rogue |
| Average | Barbarian, Cleric, Paladin, Ranger, Wizard |
| High | Bard, Druid, Monk, Sorcerer, Warlock |
The Fighter is the best first character in the game. You hit things, you get hit, you stand up again, and you learn the rules without also learning a spellbook. Want magic anyway? The Cleric and Wizard rate Average, not High.
Step 2: Pick a background and a species
Background is what you did before adventuring. In the 2024 rules it also decides where your ability score bonuses go and hands you a starting feat. The SRD includes four: Acolyte, Criminal, Sage and Soldier [1]. The Soldier boosts Strength, Dexterity and Constitution, exactly what a Fighter wants.
Species (the 2014 books said "race") sets your size, speed and a few special traits. The SRD offers Dragonborn, Dwarf, Elf, Gnome, Goliath, Halfling, Human, Orc and Tiefling [1]. None is a wrong choice. Pick the one you want to be.
Step 3: Ability scores
Three methods, all official [1]:
- Standard Array: 15, 14, 13, 12, 10, 8. Assign them however you like. Best for a first character.
- Point Cost: 27 points to spend; an 8 is free, a 15 costs 9.
- Random: roll 4d6, drop the lowest die, six times. On the 3D roller, set four d6 and press Drop Lowest.
Rolling is more fun and less fair. We counted every one of the 1,296 ways four d6 can land: one 4d6-drop-lowest roll averages 12.24, reaches 15 or higher 23% of the time, and makes an 18 just 1.6% of the time (21 ways in 1,296). Six rolls sorted high to low average about 15.7, 14.2, 13.0, 11.8, 10.4 and 8.5 (200,000 simulated characters), so the average roller ends up slightly ahead of the Standard Array and one bad evening behind it. The full comparison is in the best ways to roll ability scores.
Then add your background's bonus: +2 to one of its three abilities and +1 to another, or +1 to all three, never above 20 [1].
Step 4: Turn scores into modifiers
The modifier is what you actually add to rolls: subtract 10, halve, round down [1].
| Score | 3 | 4–5 | 6–7 | 8–9 | 10–11 | 12–13 | 14–15 | 16–17 | 18–19 | 20 |
|---|---|---|---|---|---|---|---|---|---|---|
| Modifier | −4 | −3 | −2 | −1 | +0 | +1 | +2 | +3 | +4 | +5 |
A worked example
The SRD's suggested Standard Array for a Fighter puts 15 in Strength [1]. The Soldier background adds +2: Strength 17, modifier +3. Add the +2 proficiency bonus, and your attack roll is d20 + 5.
A Goblin Warrior has AC 15 [1]. You need 10 or more on the die: 55% to hit. With Advantage, 80%. You now know more maths than most people at the table.
Your first combat
Everyone rolls Initiative, a Dexterity check, and acts from highest to lowest. A round is about 6 seconds of game time [1].
On your turn you get:
- Movement up to your Speed (usually 30 feet, or 6 squares on a grid).
- One action: Attack, Dash, Disengage, Dodge, Help, Hide, Influence, Magic, Ready, Search, Study or Utilize [1].
- A bonus action, only if something on your sheet gives you one.
- One free object interaction, like opening a door or drawing a sword, during your move or action [1].
Four actions worth knowing by heart [1]:
| Action | What it actually does |
|---|---|
| Dodge | Until your next turn, attacks against you have Disadvantage (if you can see the attacker) and you have Advantage on Dexterity saves |
| Help | An ally gets Advantage on their next check with a skill you have, or on their next attack against an enemy within 5 feet of you |
| Hide | DC 15 Dexterity (Stealth) check while out of every enemy's sight and heavily obscured or behind three-quarters cover; success makes you Invisible until you make noise, attack or cast a spell with a spoken component |
| Disengage | Your movement provokes no Opportunity Attacks this turn |
When you drop to 0 hit points
You roll a death saving throw at the start of each turn: a plain d20, 10 or higher succeeds. Three successes and you stabilise; three failures and you die. A natural 1 counts as two failures, and a natural 20 brings you back with 1 hit point [1].
We worked it out for a character nobody helps and nothing hits again: 41% stabilise, 18% leap back up on a natural 20, and 40% die. That is nearly a coin flip with your character on it. Heal your friends. A Healing Word from across the room ends the whole problem.
Magic, in four lines
- Spell slots are your fuel. Most casters get all of them back after a Long Rest [1].
- Cantrips cost no slot; cast them all day [1]. Fire Bolt is the wizard's crossbow.
- Spell save DC is the number your enemies roll against.
- Concentration: some spells last only while you focus. Start another Concentration spell and the first one ends; take damage and you make a Constitution save to keep it [1]. This is the real reason a wizard cares about Constitution.
Every SRD spell has its own page in our spell list, dice already worked out.
Beginner mistakes worth skipping
- Dumping Constitution. The SRD's own suggested arrays put 13 or 14 in Constitution for eleven of its twelve classes (the Bard gets 12) [1]. The designers are telling you something.
- Standing still. Movement costs you nothing. A step behind a pillar often beats anything else you could do that turn.
- Reading the whole rulebook first. Learn the D20 Test and your own sheet. The rest arrives when it comes up.
- Waiting for a clever idea. "I kick the door" is a complete sentence.
At the table
- Say what your character does, not just what you roll. "I shoulder the door" makes a better story than "I roll Athletics".
- When it is not your turn, watch anyway. You learn the rules twice as fast.
- Keep notes: names, places, who owes you money.
- Hold a session zero before the campaign starts: what kind of game, how often, what stays off the table.
Finding a group
- Friends who have never played make the easiest group. Everyone learns together and nobody notices you forgot the grapple rules.
- Game stores often run beginner nights. Ask at the counter.
- Online: a virtual tabletop lets you play with anyone. Our directory lists them, every link checked by hand.
Your first character will not be optimised, your first roll might be a natural 1, and you will forget half your abilities. Everyone at the table did the same. Roll anyway.
How the odds were worked: every d20 and 4d6 outcome counted exactly, except the six-roll averages, which come from 200,000 simulated characters. Assumes fair dice and no rerolls; the death-save figures assume no healing and no further damage.
Table Talk
James: I'm rolling my stats. Where's the fun in a spreadsheet?
Rohan: The Standard Array is 15, 14, 13, 12, 10, 8. Guaranteed. An 18 on 4d6 drop lowest comes up 21 times in 1,296.
James: So you're saying there's a chance.
Rohan: I'm saying take the array, play a Fighter, and learn the D20 Test first.
James: Fine. But when I drop to zero, I roll death saves with style.
Rohan: Forty percent of the time, that style is a funeral.
James: Then here's my tip: be the friend with Healing Word.
Rohan: Mine: say "I kick the door" and stop stalling. It's a complete sentence.
James: Rohan agreed with me once. Somebody clip that.
References
- Wizards of the Coast. (2025). System Reference Document 5.2.1 (CC-BY-4.0). Sections used: "Playing the Game" (D20 Tests, Rolling 20 or 1, Combat, Death Saving Throws), "Character Creation" (Class Overview, Standard Array by Class, Ability Scores and Modifiers, Ability Score Point Costs), "Character Origins", "Rules Glossary" (Concentration, Dodge, Help, Hide), and the Goblin Warrior stat block. https://www.dndbeyond.com/srd
