The Dungeon Master.
Call them what you want -- the idea that one person creates a world while the others play in it is both the greatest strength and critical weakness of role-playing games.
How do you Dungeon Master well?
Here's the most effective beginners guide you'll ever read!
WHAT AM I DOING AND HOW DID I GET HERE?
Calm down. Take a deep breath.
You are going to hang out with your friends for a few hours. It's going to be fun.
You don't have to entertain them. You are not responsible for their fun. Your job is to present interesting situations and facilitate the game. Responding to your players, listening to what they have to say, and deducing what they are interested in, while reacting to their crazy plans, is fun for you and will insure they have a good time.
BUT THERE'S ALL THIS STUFF OUT THERE I HAVE TO DO AND HAVE TO HAVE AND IT'S REALLY INTIMIDATING.
You hang out with your friends all the time. Screw all that stuff. That stuff is there for resources when you go looking for it. You don't have to do anything, other than a minimal amount of preparation. Sometimes as little as 15 minutes.
OK SO WHAT AM I DOING?
You are preparing an environment for your friends to adventure in. Some games come with a strong built in structure (Shadowrun, Dungeons & Dragons). Some games come with a player driven structure (Vampire: The Masquerade).
You come up with an idea or structure for the adventure.
It is ok, and certainly a good idea, for your first game to be explicit about this structure! You can simply say "You have gathered together to explore the mystery of the Dungeon of Dragon Mountain for the reward offered by the town council." Or "You meet with your Johnson and he tells you the mission is to extract a Saeder-Krupp employee for 10,000 credits each." Or "You have all gathered together to meet the Prince of Hot Springs. He says your first task as his subjects is to clear out a gang of drug dealers operating out of one of his bars."
Remember. The Play is the Thing.
Well, you flesh out the structure of the adventure.
How do you do that?
It's up to you!
See, you are the one who is going to be running this adventure. You should prepare it in a way that works for you.(1) You know best how you work. Here are the basics:
All traditional role-playing game design is effectively the same. Your players will be playing characters that will be interacting with you and each other in a scene. These scenes will have some method of connecting with each other.
In each scene you will have one or more of six things.
An antagonist, a reward, something unusual, a plot twist or unexpected challenge, something bad or harmful or nothing (Monster, treasure, special, trick, trap and nothing)
Essentially yes. You should conceive or design at least 5 of these to last for a four to six hour session. Some games (like in Dungeons & Dragons) it's very easy to conceive of more so that the players can choose which ones they want to encounter. But it isn't terribly difficult in other games either. A successful scene in Vampire, for example requires nothing but an antagonist.
Even in free form games these connections between scenes can be explicit. In a dungeon your exits and corridors act as connections between the scenes, but even in a game like Vampire, after the prince gives you your mission, you can say "Do you wish to contact the Justicar for supplies, Jeff's sire for guidance, or return to your haven to plan?"
For creating your first session, that's it!
In general, your game is improved by having a scene for each of the following five items.
- Puzzle or Role-Playing Opportunity
- Red Herring
- Climax, Big Battle, or Conflict
- Plot Twist
THIS SEEMS TOO EASY
Oh yeah? Let me tell you how you're going to screw it up.
You are going to imagine an exciting scene and then be tempted to try to force it to happen. Don't. This is agency destroying.
You are going to imagine a wonderful NPC, and then have him do all sorts of cool, bad-ass things. Don't. Nothing is less fun then sitting listening to how awesome someone else is. Seriously. The Worst.
Fudging the game. If you feel the need to fudge (change) a die roll, then you rolled a die for something you shouldn't have. Be very careful! If you are playing with adults, letting bad things happen to them will benefit the game, because then their choices have meaning. It is important that players feel a sense of agency. This includes such traditional errors such as having the bad guy escape/teleport away at the last second.
Attempting to dictate player actions. Don't. You want to know what's worse than a conversation about religion or politics? A discussion about what someone's character should do! Like any conversation not based in verifiable fact, it goes nowhere. Worse, the player takes it as a personal critique. If the players behavior is disruptive, then it should be dealt with directly and assertively; not using the argument 'your character wouldn't do that' to avoid a confrontation.
Opening your big fat mouth about what you had planned or what they missed. Don't. Talking about this stuff makes the game less fun for the players. Let them enjoy the sense of mystery.
Wanting things to happen. Let it go. No, Let It Go. Really. Let them miss the treasure or avoid the encounter. It feels like you are wasting work or they are missing fun, but in the end your players have to have the freedom to fail. There are always ways of reusing content.
Making the players jump through hoops. Don't. If it seems like they are about to make a colossally stupid decision then you have failed to communicate well. Don't punish them because you presented a situation poorly; clear up the misunderstanding. This can also be known as pixel bitching.
You may think there's only one solution to your situation. There's not. Design encounter with flexible solutions and allow the opportunity for your players to come up with their own solutions.
Some general advice.
Consistency. Prepare in a way that's clear to you and take a moment to write down things that you develop in play, like names of NPC's (or if you're really dedicated, record sessions).
Don't worry about rules. If you're smart enough to be running a game, you probably don't need to be told this, but you might have some compulsion or hang-up on 'doing it correctly'. Don't waste time during the game looking for the correct rule in the book. Make a judgement call and move on. Look it up later.
Listen to player comments, both in game and out of game. Let them know how you will address their actions in the future. Don't defend or debate your previous choices. Simply acknowledge what they are saying.
Involve the players. Remember, the game is about player choices. They are playing a game. If you just have them sit there powerless to affect things that are happening they will not be having fun.
Make sure the players are informed about their options. A choice between two identical dungeon corridors isn't a choice. It's a random selection. Make sure that for any choice, the players are given at least one piece of information about that choice.
A final word. A lot of advice is about how to handle problem situations. But the fact is, if you are having problems situations often it isn't a problem with the game. It's a personal issue. If you think to yourself "Ah-ha! He didn't say he lit a torch! Take 1-6 damage because you fall in the dark!" you do not need advice on how to DM. You need advice on how to get your needs met in an appropriate way in life.
(1)This could be different locations in a sandbox environment, Designing a flow-charted space or sequence of events, (making sure you do so in a format that's useful to you). or using a more advanced technique, such as outlining a spider web of non-player character influences.