Perception is everything
Just started my first long term game (after years and years of being a player)
Personally I think that talking about "sub-plots vs. main plots" and so on kind of misses the forest for the trees. Here's my breakdown.
There are two questions:
1. What makes a good game?
2. What is a good way to game master?
A good game is where a bunch of people who like each other (ideally friends) get together to play in character, over come challenges and accomplish goals (or feel a sense of acompishment) and have fun in a world that feels accetably real to them.
A good DM makes this happen.
Ideally
the people should like each other (I'm not afraid to work things so that irritating people don't play in my games..... other people I know feel like they should include everyone... its a personal kind of choice.)
they should have characters that they like, feel like they had a say in creating and which have backgrounds that are tied into the world.
well done backgrounds give people motivations to do things, they cause characters to seek out challenges and thus have the opportunity to overcome them and feel that sense of accomplishment. Characters who are overcoming goals for personal reason (vs. get xp, get treasure) feel a lot more accomplishment.
realism is the hardest thing to talk about. The best thing to say is "go nuts". Do funny voices, gesticulate wildly, tell them exactly what it is you're seeing in your minds eye. if the world lives and breaths in your mind then it will just come out if you throw yourself into the game.
One think I think people are missing or not saying directly:
Perception is everything.
Its doesn't really matter whether the PCs -are- the center of the universe, or whether you make up 70% of the game on the spot. So long as people feel like you've planned everything out for weeks in advance and it was only their brilliant thinking that allowed them to escape what you though was a death trap then everything sort of falls into place.
Likewise the PCs could spend (and I've done this) the whole game doing things that seem irrelivant but turn out later to be extremely important. Some players handle this better than others.
Dungeon craft had the best advice I've seen in a while: "don't over create". Keep things vague until you absolutely need to make a key decision.
FOCUS ON THE NEXT GAME SESSION. Its the one that matters. You'll have the week after to worry about the next one.
There will be lots of crisis moments were people do unexpected things and you wind up making things up on the spot. You won't have time to think much, just go over things for a second and say whatever comes out of your mouth. Write down a note or two about it and worry about it later.
Listen. Talk to the PCs after the game (having dinner together is good) find out what they think but not by asking just let them talk. Send out plot summaries after each game so people remember what happened (you'll usually get replies from people that give you good hints about how the game went for those people).
My personal taste is to avoid big pushy metaplots. The big metaplot should be like it is in a good CRPG..... its always there and its always looming but the PCs aren't constantly forced to go after it. I like to let the PCs feel like they can do anything they want and just run with it.
Let PCs know that they're "creating the character WITH you" and that sort of thing. Change things in their backgrounds (sometimes telling them sometimes not). Each character needs the following
1. They're from some place (especially if its "some village" you need to know about that village). I like making people from weird places. Its easier.
2. Everyone has family, especially parents and brothers and sisters, one mentor and at least one childhood friend. They can call on these people in game.
3. Everyone has one immeadiate sort of goal as a result of their background ("reclaim the lands stolen from me" "find my missing mother" "I'm dying of a strange disease and I must find the cure" -- these are all currently from my game and they were all made up by-the-players).
4. Everyone's background has a secret that's going to shock them when they find out about it. (Dungeoncraft on the WotC site was dead-on about this).
I (respectfully) think that creamsteak's idea about allowing anything is just a terrible idea. Let people look at everything they want, pick the most outlandish idea possible and then beat them until its actually playable. In general anything that you think is "too weird" is fine. (its not weird it just seems like it now) anything that would break the game is not. Any player who wants to play a "new class" should keep the same character idea but make that character a core class. I think letting Pcs make their own Prestige classes is just a terrible idea but mostly because you need to redo it to make it work 90% of the time. If you have the time and know the rules better than your PCs then its not the end of the world.
Give people "character treats". In parituclar magic items. Attach catches to the magical items. In particular give pcs who seem to want the "extra power". Pretty soon they learn that they can have lots and lots of powerful




.... but they'll wind up regretting it. Its a tough line to follow but its the best way to go.
Don't roll abilitiy scores at lower levels. Don't roll hit points. Which is to say "you can roll 4d6 like in the PH. You can keep those scores or use 32 points to build your scores like in the DMG". "Everyone rolls hitpoints. You can keep that roll or take 8 points for d10, 6points for 8d, 4 for d6 or 3 for d4". Making PCs more powerful just means that they won't die randomly as much. Just give NPCs 50-80% of their total and move along. I've never understood the whole rolling thing.