I do believe that running a fun game is more art than science, and also very individualized - so much goes into it: organization, creativity, improvisation, theatricality, social mediation, and most importantly, inspiration - that doing well at it is very dependent on finding your own strengths in those groups. So this is pretty 101, but here are the three essential ingredients to a fun table experience:
- The players need to be invested in what's going on. No shit, sherlock, but this is the sell - what a game master is jazzed about needs to be sold to the rest of the table. The fiction of the game has to push the right buttons, whether emotionally poignant or intriguingly mysterious, or just good ol' bloody-handed carnage and deserved justice. The Wahoo factor is always going to be the primary driver of the game.
- Players need to be able to believe that what's happening, could happen. Verisimilitude, realism, simulation, whatever you wanna call it - it gets a lot of flack and mockery in a hobby that's often about elves or weird magic or dragonchicks with boobs or all manner of clichés - but the importance is there. Not a belief as in "this could happen in real life", obviously, but within the fictional context of what's been constructed, what's going on in the game has to make enough 'sense' that the group is appreciative of the sequence of events and can speculate on what can happen next.
- Players need to feel like they can affect what's happening. The importance of this is certainly demonstrated in all the arguments against railroading we've seen over the years. What I find interesting is that a lot of comparison and D&D system warring seems to come down to similar arguments about player freedom, with the conflict between the rules "protecting" the player's agency (and the balance with each other) against constraining the possibilities within the game. Regardless, I think this is ultimately a responsibility the game master ends up holding, and how they handle it can make or break the experience.
I think there's something to be said for recognizing these ingredients at heart, not so much in the manic pursuit of them but more in terms of maintaining a quiet awareness of how/why the game is being stimulated. And they're actually pretty separated elements even if they're all answers to the same question of "Is everyone having fun?"
Some constructive thoughts to address these in order, geared towards the gamemaster:
- Above and beyond the most important thing to have - which is just constant, low-level table mood awareness; you can shore game investment up ahead of time by getting a sense of what people want in a game before you play (and then during as well). It's not so much about specific taste-catering, as tastes absolutely vary and change and everyone's got room to compromise (at least they should); but a quick talk about what particular aspects of whatever milieu you're exploring people want to see should not only ensure a higher degree of investment, but may also give you some good ideas.
- To get a little old-school, don't let the system interfere with the sense of reality (aka the classic "rulings, not rules"). If things have gotten to a point of argument over whether something would really work or happen a certain way, I think it's important to respect that that argument can possibly come from a sense of investment that needs to be encouraged. Rules are fun as little meta-arbiters of conflict and story creation/engagement, but sometimes the story is clicking along just fine by itself. As usual, Zak articulates this stuff better.
- If possible, let the players drive the events. My own struggles with sandbox gaming and player proactivity encouragement have really refined this for me, and a conclusion I'm beginning to reach is that railroading - a term that has a bad reputation far more for how it's done than for what is actually is - should largely be geared towards pacing control and not event control. Event preparation is where the game master gets all the influence. You have plenty of event control just in prepping the session and setting the situations and scenes, and figuring out the most comfortable form of "hands-off but still insistent" encouragement that works for you is pretty important.
- (Really for both 1 and 3) There's simply no substitute for a heavy-handed campaign kicker. Starting a campaign off with "you can do anything you want, what do you want to do?" is basically ASKing for option paralysis. So definitely start things off with a door being kicked in or some other "Holy Shit Something's happening!" event, but leave it to your players to decide what to do about it or decide what it means.