The term Master of the Dungeon (DM) was coined by Dungeons & Dragons © (Dungeons and Dragons or D&D) in the 1970s, to later become a general term for all those who run an RPG (However, the title DM [Dungeon Master or Master of the Dungeon] applies to the game of Dungeons and Dragons, while the GM (Master of the Game) refers to the “DM” of another role-playing game apart from Dungeons and Dragons). Being a DM seems easy; you control everything and tell people what they can and cannot do. However, that couldn't be further from the truth. You become in charge of both creating the details and challenges of the adventure, while maintaining a realistic continuity of the events in your dungeon. You must also have a good knowledge and understanding of the rules of the game. While a fair DM can create an experience that everyone can enjoy, a poor one can ruin any game. The following is biased for D&D, although it is general enough to apply to any role-playing game.
Steps

Step 1. Understand what the role of a DM is
The descriptions you may have heard of a dungeon master probably range from "the one who does all the work" to "you are god here." These descriptions are usually exaggerations of those who do not know what a DM really is or who know the extreme interpretation of a half-truth.
As a DM, you control everything and everyone who is not a player character (PC for short). That means that everything or everyone that players can come across or interact with is controlled by you. However, the goal of any RPG should be to have a fun time with everyone involved. It cannot be emphasized enough when you mean all. Your responses to the players, the situations you present, the challenges you create, the stories you create together, all of that should be balanced to provide an enjoyable experience for you and your players. You are not against PCs. If your goal is to destroy player characters every chance you get, then most likely you are doing it wrong.

Step 2. Know the rules
As the DM, you are expected to have a good understanding of the rules of the game. It may help that you think of yourself as an impartial judge; in this regard, just as a judge cannot do his job without knowing the rules of the place, a DM cannot direct a game without knowing the rules of the game. To help with this, most role-playing games provide basic knowledge books known as "Base Rule Books." Anything known as a core is what you need to have, or at least know about. With D&D, the basic books are: the Player's Handbook, the Dungeon Master's Guide, and the Monster Handbook. The rest are optional and may not be considered necessary to run a game. You describe the surroundings, direct the plot, and manage all elements of the game, including determining the outcome of battles between players and the dungeon dwellers. If your players come across a creature and choose a battle plan, it will be your job to decide the outcome, as while the rules apply specific guidelines, you can use your own judgment to determine the outcome in the best way to keep the flow going. and continuity of the game. It's a daunting task, but I guarantee it will get easier with time, patience, and practice.

Step 3. Prepare yourself
For some DMs, the thrill of writing their own adventures and stories to present to their players is the reason they lead. For others, it is because of the sense of balance it provides, or simply because of the fact that everything can be controlled; for some, it is their turn to lead the session. The ways you can set up the session can fill their own Wiki, but here are the basics for your first time as a DM. Remember that everyone will feel comfortable in different ways and that it is best to use the one that works for you. Don't try to force something that doesn't feel right. Again, the end result should be a fun game for everyone. If you feel like it's a lot of work, feel free to lower the difficulty.
- If you don't have time between games, consider directing modules. These will be presented for characters that are within a range of levels, with appropriate challenges. That's the easiest and fastest way to run a game, in which almost everything is already done for you. All you have to do is read the adventure. It is suggested that you re-read the pages in advance from where you left off in each session before starting the next, to refresh your memory of where they left off in the game.
- If you only have a few hours to spend between games: directing modules is still a good option. However, you will want to rewrite parts of the module to fit the game or particular story lines that you are directing with your PCs. Changing the description of the locations or replacing the module's found treasures with items better suited to your players are good and easier places to start. As your skill improves, you can start taking entire encounters from one module and writing them down in another. Not only does this allow you to choose the best parts of a more or less good module, but players who have already read or played that module before will be in for a surprise.
- If you have enough time or really enjoy writing fiction: writing your own adventures is a possibility. New DMs are encouraged to lead a module first, so they are only handling one large concept at a time (learn the rules). However, you will be more inclined to change things and write new scenarios. Taking published work encounters and writing the bridges between them could be a good start, and then you can slowly replace the published work with your own work.

Step 4. Take notes
During and immediately after the game session, be sure to take some notes about what the players did, what the NPCs did, how your NPCs and villains will respond to new events, the names of the NPCs you did. at the moment, and any other details that you think are important. This will help you maintain continuity, and will allow you to use previously found NPCs to make them recurring characters. The side effect of this is that it can limit the number of NPCs you have in the story, which keeps confusion to a minimum and allows for character development or more depth to enjoy.

Step 5. Be willing to make mistakes
Sometimes things will not go as planned, either because of a mistake in applying a rule or confusion about how a spell would affect an NPC, or because your adventure (the one you so carefully wrote) was put aside by the people. players because they believed that a random NPC (which you had nothing written about) was much more interesting than your "Quest to save the damsel". Problems happen frequently. The best tool any DM has under his belt is the ability and willingness to go with the flow.
- If the problem is disagreeing on how to interpret a rule, don't let that stop your game. Don't spend more than two minutes looking for it, unless the character in question can die from it. Calmly explain how that would work, decide to find her after the game or between sessions, and move on. Nothing kills a game faster than a 15-minute fight between two party members, while the others get bored. Keeping the game running fairly is better than killing the game by trying to get every detail right at every turn.
- If the problem is that the players did something that you did not plan, anticipate or want them to do, be willing to say “yes”, or at least don't say “no”. Some DMs can improvise things quickly, so do that too if you can. If you don't feel comfortable doing that, call for a little break (people can go to the bathroom, eat, etc.). In the meantime, take advantage and write down some ideas, and make a brief outline of the plan for this new direction that you are going to take, which leads us to …

Step 6. The DM's Golden Rule
Players are always going to do something you never thought of and could never have anticipated. No matter how many solutions or tangents you may have planned, chances are they will go for the one that never occurred to you. It is better to accept this reality now, otherwise you will get too frustrated, over and over again, but do not get demoralized! That detail keeps the game interesting and surprising for you, which can make you enjoy it even more.

Step 7. Have confidence in yourself
Not only will that make your game more decisive, it will also make it more fun. No one is going to want to play if the DM says, “Uh… well… you just… found a cave… yeah… that. And in the cave there is… a… imp. Eh… what are you going to do? You should say it like this: “You come across a cave, and what do you find there? An ugly imp, what are you going to do? Getting ready is a good way to build your confidence. Remember that until you say it exists, no one knows what is written in your notes. Whether you read it directly or make changes to it as you progress, unless you tell the players, they will think it was planned that way from the beginning. Use that to your advantage.

Step 8. Get involved, be creative, and reasonably realistic
Don't be bland when describing the settings; change your voice to show that you are fully into it. Adopting accents from various NPCs also adds some zest to the dungeon. Remember, the point of going on an adventure is seeing and experiencing new things. Get creative with your descriptions and settings to give each location and interaction its own taste, but don't let your imagination run wild either. There is something called "suspension of disbelief" which you will want to establish. While you are pretending to be in a fantasy world where magic is common, there are rules about how it works. Keeping your work within those guidelines can mean the difference between a captivating fantasy story and a parody where everything seems fake and silly.
Advice
- Sometimes fighting a few large monsters is more enjoyable than a horde of weak monsters. Fighting a horde of weaklings means you have to roll the die many times. Managing large monsters allows you to focus more on individual strategy.
- The start of the session: Over time, you will find that, as you play with the same players, you will be talking for a few minutes before starting the game. It's okay to do that. The conversation relaxes the players, it gives you time to check that you have everything you need and if you are ready to start, to answer any questions that the players have; You might even know how everyone has been since the last game. However, don't let the conversation last too long (15-30 minutes is fine). If you let it last longer than that, you will already be consuming game time.
- Have fun. It may seem difficult, but it will get easier and easier. Just keep having fun. If your players see that you're not having fun, they won't either.
- For first time DMs, it is best to limit yourself and your players to the options and rules in the core books ONLY. Not all additional books are balanced with each other, and this can cause one of the players to have too much power over the others, and that is not good.
- Books are not completely necessary for all players; you can play without them without problems, but at least the DM should have a copy of each, which he can share with the rest of the table.
- Descriptions are very important in D&D. Unlike movies and TV series, gamers are watching you. The better your descriptions, the more vivid the experience will be for your players, and the better your game will be. For example: a terrible stench emanates from the entrance of the cave. Water drips around the outside of your mouth, creating a couple of lines of water across the rocky ground; there appears to be a grooved channel in the rock.
- Don't deprive someone of doing something. If you are trying to get your players to go to a certain place, don't tell them: “They can't go there”; Instead of doing that, try saying something like: "A lady over there says it just happened in, Would you be interested in going there?" You can also have them roll a passive insight test to see how interested their characters might be in going there; if that's the case, make the difficulty (CD or Difficulty Class) low.
- One of the most important things for a DM is the ability to think quickly. Things are going to happen that you don't expect. Players could either kill the person they had to get vital information from, or go to the only section of town that didn't have details ready. Do it as you go, just be sure to take notes to incorporate into the story later.
- If you are just starting out, play with friends; a relaxed and familiar group of people will help to learn the game faster and better, especially when jokes can be made.
- Name List: Make a name list starting from your first game. Over time you will find yourself needing names, so start keeping track of the most interesting ones you can imagine or find (my favorite name so far is Ozell… He was a very nice guy!)
- You are not being a good DM if you only dedicate yourself to refereeing him. For example, if you always use dungeon ideas from the internet, it's okay to do that once in a while, but try to take those ideas and make them your own (create your own monsters, etc.). However, the ideal is that you create your own dungeons using your imagination well.
- Generally, there are two types of DM: the one that kills all the player characters in the first micro second, and the one that wants the characters to have an adventure; you can choose either of these two options if you want.
Warnings
- Don't be overwhelmed by the players. Your word is like divine law in your dungeon.
- D&D can be addictive, it is a game after all. Rest both physically and mentally from the game; a short 15 minute break after three hours of play could be adequate and sufficient for any DM. Don't let you or your players get exhausted (this puts everyone in a bad mood and makes the game unenjoyable).
- Distinguish when the amount of information you give to the players is too much, little or correct in quantity. Respond concisely to their answers and don't give too much information.
- Don't let the players dictate how things should be, from novels or posts. Otherwise, the one who read the thirty novels based on that world may try to manipulate you with knowledge that only that player has. In the end, it is the DM who has the final say on what exists and what does not. However, reaching a balance is best. Work with them to incorporate some of those details, as long as that doesn't give any of them an unfair advantage.
- Beware of the rules maniacs, lawyers, and meta-players, and don't play their game just to punish them. Instead, come up with interesting ways to deal with your characters in-game.
- Alignment can be a troublesome thing from time to time. Remember, being evil is not synonymous with being stupid, it is just evil. As a DM, it's your job to be all three sides: the good, the bad, and the stage.
- While you want to make your dungeon challenging, don't make it impossible. What's the point of doing something if it's going to be extremely difficult on the PC (player character)?
- Some people may think parts of your story are silly (monsters coming out of pumpkins on the farm next door, all NPCs are alien invaders) but that's their problem, not yours; after all, it's your story.
- Some people really want to learn how to play D&D; Others may simply be interested in what you are doing, and others may simply have very negative opinions. As a DM, make sure you respect these three classes of people. Doing that for the first group might get you some new players (to kick off your DM skills); for the second group, you could make some of them feel drawn to learning the game, and for the third group, you could shed light on their myths. At the very least, that will give your players an example of how to behave in those situations (as some players get extremely suspicious from time to time).