A lot of this stuff I've read here are things that are reasonably OK in moderation, but become a problem if overused...or applied to the wrong types of players. I've had groups that
needed to be railroaded. If I didn't, it became "the directionless session" On the other hand, the example used where "No matter what you do, the thingamabob will be stolen by whoseywhatsis with a whatchamacallit" is the worst kind of railroad.
Likewise if you try a mystery with dungeon bashers, you end up with "The Impossibly Convoluted Mystery That Just Won't End." It all depends on the players.
The biggest DM that "grinds my gears" is the control freak/novelist DM. Nothing you can come up with will fit his world. Even the most basic PC races and classes can and will be vetoed by this guy. He won't even negotiate. (This guy usually has an overdeveloped sense of "this is how D&D is SUPPOSED to be played") The game's all his, and you're really just a spectator. Forget gather info or knowledge skills...you don't get the info till this DM has decided that you've danced enough and he's now good and ready to give it to you.
Life's just too short to play with these guys.
A few random thoughts:
Every important NPC is the conniving DM.
Why is it when running through ye olde Convoluted Mystery every damn NPC that matters holds back as much information as possible, has to be pumped hard for any useful information even little tidbits that do not matter to the NPC, cannot offer anything like a fair deal without it being carefully negotiated for by the PCs, and are ingrateful wretches who do not volunteer information even after saving their worthless life?
Eh, gather info, intimidate, diplomacy etc are mechanics meant to help arbitrate these ones fairly. In 3x, this peeve shouldn't have to exist.
a Super-Duper BBEG from out of nowhere utterly destroys the entire region. Your background and knowledge of the local region are now completely worthless as the entire game devolves into chasing after the BBEG, never stopping long enough in one place to actually portray your character in any meaningful sense.
If my DM made me shoehorn my character into his "story" then write all the backstory etc just to pull this stunt, I would quit. I have before. (most of the players jumped ship with me too)
Just Handing Him Ammo.
Your backstory serves one, and only one, purpose: to give the badguys more way to get you. Come from a town? It'll be razed. Have a sibling? They'll be attacked, kidnapped, turned into undead, or similar. Mentor? Killed before your very eyes, or turned evil. So on and so forth. Anyone you care about will be used against you in some way. If you have noone, you're fine, but you have people in your life they are tragedy waiting to happen.
Actually, I've been guilty of this. I'm not too apologetic though. To my way of thinking, backstory is
meant to foster adventure hooks...otherwise it has no purpose other than as fluff.
His name? Uhm... Bob: The DM never comes up with names for anyone. Random NPCs is one thing, but when the PCs interact with major NPCs they find that they never have names. The town mayor, the wizard who hires them, the boy they're sent looking for, etc. None of them ever have a name! Towns can fall into this category as well.
Agreed...but there's a counter-beef here though. I go out of my way to have NPCs with good names. Then my PCs can't ever remember them. Instead it's "lets go see that hot elf chick" or "we gotta watch out for that one eyed mean guy"
NPC's from one game keep popping up in other games. "Didn't this wizard hire in the last game you ran?"
Actually, I don't see the problem here. My handle, Shadowslayer, has had cameos in every game I've run since the late 80s. (he's a half elf ranger who usually pops up as a boatman or a wanderer)
![:]](http://www.enworld.org/forum/images/smilies/devious.png "Devious :]")
The game was aborted but the DM learned a valuable lesson. 
