There are many important concepts to make sure you have hammered down with your group before you officially start a campaign. Many of these will seem like common sense but some of them are concepts that I have developed by making dreadful mistakes as a DM. For instance, most pre-written campaigns by Wizards have very poor reasons for your party to buy into the campaign. More on that later. Let's start with the basics.

The Basics

The first thing to establish with a group is the time, place, availability, frequency and way you intend to play. You have to iron out a solid schedule and that should alleviate most frustrations of a starting DM when it comes to people not showing up. Establish ahead of time whether your players can play the same time and day each week, every other week, once per month, etc.

Here are some important questions to ask yourself and your group:

• Are your sessions going to be in person or remote?
• What sort of medium will you be using to play? In person, will you use minis, theatre of the mind, or a TV with Roll20 on it? Remotely, what will you use to roll and show character tokens?
• If you are playing remote, make sure everyone that is playing actually has a good enough internet connection to work on the medium you choose!
• Are there any terms or concepts that are off limits? I am the antithesis of a sensitive DM and I love my players to tackle very complicated moral issues, but most DMs and groups now want to establish ground rules when it comes to language and behavior.
• Will treats be provided and who will be bringing them? Contrariwise, if you are remote, tell people to mute themselves while chewing. Unless you're into that sort of thing. To each their own...
• Are there any specific rules that you want to establish as a DM? For instance, I have a custom rule regarding being made prone. If you are knocked down, your next attack is at disadvantage (this makes the monk and shield master much more valuable). Make sure you establish all of your house rules in session zero.
• Will META conversations be allowed? If so, what is your word to exit META? Make sure this is something that will not be casually mentioned while in META so you don't accidentally go back into the game. My current two are 'meatball' and 'quiche'. We just have to be picky with our META conversations about dinner.
• Will you allow your players to roll against each other? In other words, if your rogue wants to steal from your ranger, will you allow them to roll stealth against the ranger's passive perception? If they start trying to convince each other, does your bard get to roll for persuasion against another party member to convince them?

Difficult Questions

Perhaps the two most important questions to ask yourself are the following:

Do you really want to DM a campaign?

Are you certain this is a good fit for you? It is a decent bit of work. Do you have the time and the patience? This may seem very obvious to you, but I have had DMs quit very quickly due to scheduling issues or just generally being very bad at it, and it can ruin DnD for potential players. As a matter of fact, I only started to DM in the first place many years ago because of a lack of availability of my first DM (Thankfully! I love being a DM so much more than playing. Thanks Jeff <3).

Does your group really want to play a campaign? Do they want to run this campaign?

Maybe your group really does not like the idea of being involved in a story that develops over the course of 30 sessions. They may just want to run mini-campaigns that only last 3-6 sessions each then build new characters for the next round. Make sure that they are willing to buy into and commit to the campaign from start to finish.

Following up on that 'buy into' concept, make sure that this is the type of campaign that they want to play in. Some campaigns are more serious, scary or challenging than others (Curse of Strahd). Maybe your party really wants to play something light hearted and fun instead (Waterdeep Dragon Heist)? I'll have a downloadable PDF for your players if you're interested at the end of this post. It should help you answer these questions.

My Advice

You do not have to agree with me on these as each DM runs their games differently, but I strongly advise taking the following into consideration:

ALWAYS run a one-shot or a few session mini campaign with potential players before you DM a full campaign with them. This is particularly important for a new player joining a campaign that is already in existence. What if everyone else in the group can not stand them? It could ruin the entire campaign that you have worked so hard to develop. Also, super awkward when you have to tell them not to come back. It is equally important, however, to run these for new groups in their entirety before you run an actual campaign. It will help them learn each other's strengths and weaknesses at the very least.

Establish a 'no touch' policy when it comes to players interacting with other players' characters. This is weird, I know, but you will be in a very awkward situation as a DM if your party's barbarian picks up your gnome wizard without permission and starts running with them. What if they did not want to be picked up? Just have them enter META and ask first. It will save you a lot of grief.

Always remember YOU are the DM, not the players. You establish the rules. Game rules from the DMG, homebrewed rules, all the rules. You are the god of your own little universe you have created. They can alter the world, but they should not be building it. That is your job.

Do NOT argue rules during game play. This ties into the previous advice. Players will disagree with a ruling sometimes and that makes sense. Maybe they are unfamiliar with it or perhaps they think it is unfair. I suggest making it a point to say, “rule questions will be answered after the session or on breaks.” It really breaks the fantasy and mood you have created by suddenly arguing about a rule for 30 minutes in the middle of a session.

Learning the Hard Way

The most important concept I had to learn the hard way was the significance of establishing why a group of adventurers is together in the first place. As I said in the beginning, a lot of the pre-written campaigns have loose or sloppy buy ins for your party. It is of the utmost importance that you write your characters into the story. What do I mean by that strange and vague statement? Tie your characters into the story with their background by adding a relationship with an NPC, a friendship or familial relation with another player character, or a tie in to the actual storyline.

Ask yourself, “What sense does it make for these people to be traveling together? Why would they be adventurers in the first place?” Once you develop concrete answers with your players on those it makes sense for them to be together and pursuing the same goal. After all, why would any party put up with a murder hobo thief that always steals from the party? Wouldn't they just kill him in his sleep? Brutal, I know, but it makes sense.

Equally important is skimming through the entire book / PDF or developing a general story web for homebrew campaigns. This will help a ton when it comes to dropping hints and developing the story itself.

Most Importantly

HAVE FUN! DMing may be a lot of work but it is incredibly rewarding. You will be surprised by the messages you'll get from your players about how amazing it is to play. Fun does not even mean light-hearted necessarily. I've had players message me about how awesome it was that their character died!

You will weave some very awesome stories with your friends. You are creating a world for others to play in and develop stories about. Characters will become legends. Villages will develop into cities. NPCs will make appearances again and be fun Easter Eggs (ironic given the date) in future campaigns. You will make the sort of stories that years later they'll bring up and you'll have a laugh about. Perhaps a tear or two, if that's your sort of thing.

As Promised

Check out this Questionnaire PDF. It's not for everyone, but it definitely helped two of my groups and I to get on the same page regarding their expectations and matching that to the proper campaign.

Also, here is a New Adventurer Primer for people that are looking to play in your campaign. It is a very basic run down of what they can expect to experience in DnD 5e.