The Big Goal: Run a game where everyone is able to have fun.
Of course. It doesn't matter whether you're playing D&D, Spirit of the Century, Descent, or even Vampire, the end goal ought to be a game where everyone is able to have fun. A game where everyone has fun is better, but it's not something you're in charge of. If Tammy's dog got run over last week, and she's still broken up about it, she might not have fun no matter what you do, and attempts to get her to have fun could result in less fun overall.
So what goals are going to help create a game where everyone can have fun? A lot, but here are the ones which seem most important.
- Create a vital setting
- Cultivate a vibrant style
- Create a safe space
- Treat players with respect
Create a Vital Setting
Why? A setting that seems alive, with events happening all around, as well as with the player characters gives players more options. The idea that things are happening off-camera helps create an immersive world, and immersion increases people's ability to have fun.
How? A sandbox GMing style works well for this, with pre-established chains of events that the PCs can influence by interacting with them. Creating a rumour mill or toown crier network throughout the setting will allow PCs to hear of events going on in distant lands, which may prompt them to go there. Semilinear styles can work for this as well, allowing you an avenue with which to pitch adventures to the party.
Cultivate a Vibrant Style
Why? An adaptive style with good descriptions of scenes is going to speed up play and keep people involved. Short, visceral descriptions allow people to ask more questions, and you won't run the risk of them getting bored. Boredom is the fun-killer. It is the little death that brings total distraction.
How? There's an old saying, "Show, don't tell". All players have to rely on for what the world looks like are their imaginations and your description. You're not in charge of the former, so make the latter as good as possible. And better does not mean longer. Use visceral terms, or common sympathetic elements (I could do a dozen posts about those). Write down little snatches of descriptions you might use, and give yourself a word limit for them. Or practice by stopping periodically throughout your day, looking around you, and just describing what's going on in as interesting a way as possible.
Create a Safe Space
Why? This is second only to treating players with respect. Roleplaying games are about theatre and escapism as much as math and mini combat. People are acting out, pretending to be things they're not, whether that's elves or villains. That's a big part of what makes it fun. But people are less inclined to do those things if they think they'll be judged negatively by their peers for doing it, whether that's by people outside the game thinking they're nerdy, or other players making value judgments about their character decisions. This isn't to say that criticism shouldn't be valued, but that it should be framed constructively, and the basis for it ought to be examined. If someone wants to play the villain, or do a bit of gender-bending, why shouldn't they? If you're playing Rifts, D&D, Mage, or Call of Cthulhu, you're already imagining things which are way stranger, and not batting an eye.
How? Look to the needs of your players, and balance them with the logistics of the gaming group. If people are getting self-conscious about being nerdy, try to avoid playing in public places. If they love moving around and being wildly animated, try playing somewhere with a bit more space. Most importantly, try and cultivate a safe space within the gaming group by maintaining a positive and encouraging view on people's ideas, no matter how strange they seem. People who are comfortable will be more immersed in their characters, and thus more immersed in the game, which means they'll be able to have more fun.
Treat Players With Respect
Why? This is without a doubt the most important one. Sure, there's a time and place for adversarial GMing, but if you're trying to have a character driven game (and you probably are, because if you're looking for the player-driven tactical game, you should all probably go play World of Warcraft, Team Fortress 2, or even Risk. They'll supply those elements in spades) you need to respect your players' choices. Nothing kills someone's fun faster than the stonewall "It doesn't work" or the sense that their choices don't matter. Everybody's guilty of this now and again, and all you can really do is try and be conscious of it. Players are not your enemy. They are not whiny babies who want more points. They're people you sit around and cooperate with in order to have fun. If that's not the case, you might be playing the wrong kind of game.
How? Lots of little ways. Follow the rules, for instance. Players rely on the rules to tell them what the world is like, so try and follow them as best as you can. Try and find ways for people to be able to do things, rather than ways that they can't. Burning Wheel is really good for this, establishing stakes before dice are rolled. Spirit of the Century as well, with its negotiation mechanics, allows people to examine what they want from an encounter and then everyone tries to find a way to reach it. View your players as shareholders, rather than adversaries. They have a stake in what you do, and you have a stake in what they do. That makes their considerations relevant, and if they know that you're behaving that way, it creates an atmosphere where they can have more fun. They'll trust you, and as long as you don't betray that trust, you can get a fair amount of leeway.
These are just some of the minor goals that can help you achieve the major one, and I could really do a post on each one, but I wanted to start with an overview.