The GM should know the rules inside out, as well as when to break them and when to stick to them rigidly. They should also know the scenario, by reading through it at least twice, and also know the wider campaign and the world it’s set in. The GM should know the players. What they like, what they dislike, what they pretend to dislike but always seem to get more involved with. The GM should also know the characters, have copies of their character sheets to hand at all times, and have a note of their basic stats right in front of them.
Most importantly, the GM should know the players, including themselves, are there to have fun, and to empower that fun for all concerned.
I’m not talking about the ability to put both feet behind your head, but to alter the flow, mood and speed of a game session according to the preferences of the players. For instance, if the player who normally pushes the game on is absent for a session, game progression might slow to a crawl. The GM will have to take steps to keep things moving. Or maybe the players are in an upbeat mood, and the session you have planned for this week is very dark and sombre. In this case you might want to change the events so the dark and sombre comes at a more appropriate moment, which means you’ll have to change your plans at a moment’s notice.
This might not seem like an important skill, but players come from all walks of life and have different attitudes, (baggage!) to prove it. Some people think gamers are all young, white men, intelligent and a little odd. While the intelligent and odd might be true for most, the young, white, and men parts definitely aren’t. Which means a GM could be dealing with people who are very different to themselves and to the other players. It’s obvious you can’t please all the people all the time, and so have to be diplomatic when making decisions, particularly if they had a good effect on one player and a negative effect on another.
During a particularly rowdy game session, the GM could be asked the same question by every player over the course of several minutes. The GM should answer each one fully and patiently, it’s not the player’s fault if they didn’t hear the previous answer because of all the noise. Or maybe the players are having a dull moment and just can’t guess the answer to a problem you think is easy. Don’t forget you already know the answer, which makes it seem easy to you. Just keep giving them clues until they get it, you can always reduce the XP given at the end.
6) Good Listener
This is particularly important the more players you have. Each one wants to have their say and take their actions, so you have to listen to each in turn. But the players might all have different ways of speaking, so the GM also has to understand what they say, not just hear the words. This is why turn-based systems are used. Each player gets their few minutes of GM attention, during which time they should ignore everyone else as much as possible.
This might seem like an unimportant skill, particularly if you only run pre-written campaigns. But if you want to write your own, or even just customise the ones you buy, this is important, particularly if the players are more experienced and have seen it all before. In order to keep things fresh, the GM must come up with new ways to threaten the players, new NPCs and new locations.
Imagination is also essential to putting the NPCs you play into the setting, to allow you to think more like them, and participate in the game, the GM is also a player after all.
4) Good Planning
Good planning is essential for any GM, not just the scenario you’re playing, but at least two or three ahead. That way you know what’s coming up, and can head off any problems in time. Always read the scenario before the session, and refer to it during, make sure you know what’s happening and why, what the player need to do, and any items that are essential to the success of it. For instance, if the whole adventure revolves around the characters having a specific artifact or a scroll to decode a locked door, you’ll need to make sure they have it, by whatever means necessary. And that means putting it somewhere they can find it, and even moving it if they miss it the first time. (Done that one a few times! Once with an entire building!)
Good plans should also include things like dealing with deaths, characters getting lost, upsetting NPCs, missing clues and generally not behaving as they should.
3) Quick Thinking
Good planning and preparedness can reduce the need for sudden changes and actions, but things can still go wrong. The GM might also come up with a better idea halfway through a scenario and have to change something on the fly. Sometimes, particularly if you write your own stuff, things might not work as you planned, and you have to start thinking on your feet to save the situation. Having material planned for such events as character death, whole party deaths, characters going the wrong direction or missing vital clues are all times when quick thinking is needed. Depending on what type of GM you are, this can be bad or great fun. I once ran a full session making it up as I went along after the PCs completely misinterpreted a clue, and it was great fun for all.
2) Good Story-Telling
I think this one is pretty essential for any GM. This isn’t just about reading the text in the scenario, but acting out the NPCs, making PC interactions with NPCs interesting, making sure combat is exciting, and that the whole adventure tells a decent story from beginning to end. You don’t have to be a Benedict Cumberbatch, but being at least able to do a few voices and some mannerisms is a great way of letting your players know they aren’t talking to you, but to a person within the game. You don’t have to create a whole persona complete with speech patterns and gestures for every NPC the players encounter, but doing this for the most important ones really helps. Giving NPCs voices that don’t match their character, like a troll who sounds like a small child or a politician, is a good way of making lighter moments among all the action.
If you aren’t so good at this kind of thing, you can learn about it. You can read up on drama, acting, voices, story construction, etc. You can also get advice from other GMs and players, asking them for feedback on your performance. Most of the time the story will flow along with the gameplay, but sometimes the GM is the sole focus of the players, and is carrying the story on their shoulders.
A good GM arrives at the session venue in good time, with everything prepared and ready, with enough material to keep the players occupied for that session and preferably a few more in advance. If this isn’t going to happen, and real life can get in the way without notice, the GM should be able to contact all the players and warn them of their late or non-arrival. With today’s modern technology this shouldn’t be a problem. This sounds like a serious thing for what should be a fun game, but it’s only fun if the players are there and everything is ready. In some cases, people travel relatively long distances to play, and not being there, or being there unprepared is a good way of losing players. Sitting at a table set out for gaming with one or even no players at all is not fun for anyone. And eating all the snacks and drinking all the beer alone is definitely not good for your health.