How to DM Your First D&D Session

What does a Dungeon Master actually do?

The Dungeon Master (DM) runs the game for everyone else. You describe the world, play every monster and non-player character (NPC), decide what happens when the players act, and apply the rules. You are the referee and the narrator, not the players' opponent. Your job is to give the group interesting choices and a fair, fun session.

You don't need to be an actor or a rules expert. A first-time DM needs four things: a short adventure, a few notes, a way to roll dice, and a way to track turns in combat. For the last one, an initiative tracker keeps the turn order and everyone's hit points in one place, so you aren't juggling scraps of paper.

What is a session zero and why run one?

A session zero is a short meeting before the real game starts. It takes 30 minutes to an hour and saves you from most of the problems new groups run into. Cover these points:

• Tone: is this a lighthearted romp, a heroic quest, or a grim horror story? Agree before anyone builds a character.
• Content limits: ask what topics players want kept out of the game entirely and what can happen only off-screen.
• Schedule and length: how often you meet, how long sessions last, and what happens when someone can't make it.
• Table rules: phones, side conversations, how you roll (physical dice or an online roller), and whether players can see each other's rolls.
• Characters: make sure the party has a reason to work together. Building characters together at session zero helps.

What safety tools should a DM use?

Safety tools are simple agreements that let players steer away from content they don't want, without a long discussion mid-game. Two common ones:

• Lines and veils: a "line" is something that never appears in the game. A "veil" is something that can happen but is summarized or "faded to black" rather than described in detail. Collect both at session zero.
• A stop card: an index card (often marked with an X) in the middle of the table. Any player can tap it, and you skip or rewrite the current content, no explanation needed. Online, a typed signal in chat does the same job.

Treat these as normal parts of the game, not a sign that something went wrong. They work best when the DM uses them too.

How do you choose your first adventure?

Pick something short. A one-shot or a starter adventure that covers one to three sessions lets you learn without committing to a campaign that might collapse. Good first adventures have a clear goal, a small area (a village, a cave, a single dungeon), and a handful of fights.

A published adventure or starter set is the easiest route: the maps, monsters and NPCs are written and the fights are already balanced for the party. If you'd rather write your own, keep it to one location and one problem, such as "goblins have taken the mill and the village needs flour before winter."

How do you prep a D&D session?

Don't write a script. Players will do something you didn't plan for in the first ten minutes. Instead, prep the pieces you can use no matter which way they go:

1. Hold a session zero to agree on tone, content limits and schedule.
2. Choose a short adventure that fits one to three sessions.
3. Write a strong start that drops the players straight into action or a clear problem.
4. Outline three to five possible scenes instead of a fixed script.
5. Prepare the key NPCs with a name, a goal and one memorable trait.
6. Build one or two encounters and check their difficulty.
7. Decide on rewards such as treasure, information or a favor owed.
8. Plan an ending hook that makes the players want to come back.

What makes a strong start?

Open with something happening, not with the characters meeting in a tavern and wondering what to do. A cart crashes in front of them, a messenger collapses at their feet, or the floor of the inn gives way. A strong start gives the players something to react to in the first five minutes and answers the question "why are we here?" right away.

How much should you prep for scenes and NPCs?

Write three to five scenes as short situations, not plots: a location, who is there, and what they want. For each important NPC, note a name, what they want, and one trait the players will remember, such as a nervous laugh or a pet crow. The NPC generator is handy for the extra shopkeepers and guards players will inevitably talk to.

How do you build encounters and rewards?

Plan one or two fights for a first session, plus a social or exploration challenge. Check each fight's difficulty against your party's size and level with the encounter calculator. The 2014 rules rate encounters as easy, medium, hard or deadly; the 2024 rules use low, moderate and high difficulty budgets. For a first session, lean easier than you think, since new players take time to learn their characters.

Rewards give the players a reason to take risks. Mix treasure with information, allies and favors. If you need a quick treasure hoard, roll one with the loot generator before the session and note it down.

How do you run the session at the table?

Most of a session is a simple loop:

1. Describe the scene: what the characters see, hear and smell, in two or three sentences.
2. Ask the players, "What do you do?"
3. Listen to their answer and decide whether the outcome is certain or uncertain.
4. If it's certain, tell them what happens. If it's uncertain and failure would be interesting, ask for a roll.
5. Describe the result, then go back to step 1.

Keep descriptions short and end them with a question. Look around the table and make sure quieter players get a turn to act, not just the loudest one.

When should a DM call for a roll?

Only ask for a check when two things are true: the action could fail, and failing would make the story more interesting. Opening an unlocked door needs no roll. Picking a lock with all the time in the world and no danger nearby doesn't really need one either; the character just succeeds eventually. Picking that same lock while guards are walking up the corridor is worth a roll.

A failed roll should change the situation, not stop the game. The lock holds, but now the guards are here. The climb fails, but the character finds a different route and loses time. More on how checks work is in skill checks in 5e.

How do you set the DC for a check?

The Difficulty Class (DC) is the number the player must meet or beat with a d20 plus their modifier. The rules give a simple ladder, and it is the same in the 2014 and 2024 rules:

Most checks should be DC 10 or 15. A character with a +3 bonus succeeds 70% of the time against DC 10 and 45% of the time against DC 15, so DC 20 and above should feel rare and dramatic.

How do you run combat as a new DM?

When a fight starts, ask everyone to roll initiative: a d20 plus their Dexterity modifier. Roll once for each group of identical monsters to keep things quick. Then go in order from highest to lowest, and repeat each round until the fight ends.

• Track the order: enter everyone into the initiative tracker and tell the next player they are "on deck" so they can plan ahead.
• Track hit points: keep monster HP on your side of the screen. Tell players how hurt a monster looks ("bloodied," "barely standing") instead of exact numbers.
• Describe the hits: say what a hit or miss looks like, not just the number. It keeps combat from becoming arithmetic.
• Let monsters flee: most creatures don't fight to the death. A goblin that runs or surrenders ends a slow fight and can become a useful NPC.

If a fight turns out much harder than planned, adjust: have reinforcements fail to arrive, let a monster retreat, or give the players a way to escape. Nobody needs to know.

How do you end your first D&D session?

Stop on a hook, not in the middle of a lull. A good ending is a cliffhanger (the ceiling starts to collapse), a revelation (the friendly innkeeper was the cult leader), or a clear next goal (the map points to a ruined tower). Leave the players something to talk about until the next game.

Then take five minutes to ask what everyone enjoyed and what they want more of. Write it down; it is the best prep you will get for session two. When you're ready to sharpen your skills, see our dungeon master tips for quick fixes to the problems every new DM hits.

FAQ

How long does it take to prep a D&D session?

It varies by DM and adventure. A published adventure needs less work because the maps, monsters and NPCs are written for you; a homebrew session takes longer. Many new DMs find that prepping a few scenes rather than a full script saves the most time.

Do you need to know all the rules to be a DM?

No. Learn the core d20 roll, how checks and DCs work, and how a combat turn runs. Look up anything else when it comes up, or make a quick ruling and check the book after the session.

What is a session zero in D&D?

A session zero is a meeting before the campaign starts where the group agrees on tone, content limits, scheduling and table rules, and often builds characters together so the party fits the adventure.

What DC should I set for a skill check?

Use DC 10 for an easy task, DC 15 for a medium one and DC 20 for a hard one. DC 5 is very easy, DC 25 very hard and DC 30 nearly impossible. Most checks in a session fall between 10 and 20.

Should a new DM use a published adventure?

It is usually the easiest start. A short published adventure or starter set gives you a tested plot, maps and balanced fights, so you can focus on learning to run the table.

Related

• DnD Initiative Tracker
• Dungeon Master Tips: 20 Practical Tips for New DMs
• Skill Checks in 5e: Full Guide
• Initiative in 5e: How to Roll for Initiative and Track Turn Order