Hi, I'm an unsuccessful forum game GM. Here's what I've learned about the whole process. Some of this is going to be repeats, but I feel they are important enough to mention again.
1) Consider your own personal time. Critically analyze your schedule for the next four weeks before even thinking about starting a forum game.
Players will drop out very rapidly if you don't post a turn least every other day in the first 20 or so turns.
Look at all the longest running forum games, they all have a GM who is willing to post multiple turns a day or post turns that are several hours of writing
per player. And they do it consistently, for weeks on end.
I have learned that it takes at least 1 hour for a good but short turn, and realistically 1.5-2 hours for a turn that players enjoy. In my own personal life, I don't have the ability to spend 6 hours a week on running a single forum game, so that's basically why I quit doing it.
2) Keep overhead low. Making maps, adding pictures... all these items make you a more popular GM, but take time. Time that keeps you from doing the core of the forum roleplaying game - which is resolving player turns. If you have to do anything, a light usage of pictures is probably best, and don't spend any time on them.
3) Try it out. I can't stress this enough, because almost everything I've learned about being a GM comes from experimentation.
I have conducted a lot of games which were never intended on being a full game, just a little fun to figure out how to be a better GM.
Here's an example :
Outlaw Biker :
http://www.bay12forums.com/smf/index.php?topic=96671.msg2774721#msg2774721This is decidedly a "simple" game. I was using it to test simple combat mechanics, short responses, and organizing the game space. The results I got from this : Even simple combat can take a lot time, 4 players is probably the optimal number for my own personal time constraints, and you can have fun even with a "short" story.
4) Drop unproductive games. If you have a game which you are no longer in love with, don't do it. There's nothing more frustrating than feeling compelled to write yet another turn for a game you hate. All your good story ideas will be wasted if the game inevitably fails, so save them for another time.
If you have argumentative players, unresponsive players, trolls, etc. either drop them out of the game (kill their character) or quit the game altogether. Some games are never going to be successful on the Bay12Forums, and that's a fact of life.
And now to conclude...
5) Don't force a story down the players throats.
One of the most enjoyable times I had as a GM was when I made a game which was essentially a story. It has a very linear plot line, so I didn't have to do much creatively each turn. Once I figured out the basics of each character, I just wrote turn after turn of what they were doing, without really
listening to the players. The problem is, that's not a game. That's just fanfic writing.
A game is dynamic, both the players and GM must make the 'story'. As a GM , you should enjoy what you are doing, but remember that the players are there for enjoyment too.