It a matter of time mangement for both player and DM.....Cause I do not want to waste 2 hour of real time to map out huge map of nonthingness. I want the roll play and role play time. Not mapping nothingness. So speed up the pre-fight stuff and get to game. Just remember to keep it balenced and fair what is good for player is good for GM.
I figure if my players have a fair idea of there's combat on the other side of the door then I'll allow two rounds of buffing before they have to open it. They can try buffing for a third round but then there's a chance the enemy will make a move by then. By the forth round of buffing the enemy is attacking.
Serious reconnaissance and spells like teleport can change all this and I like to keep it all fluid anyway.
The way I see it, if I don't occasionally give them time to buff then abilities like the Paladin's bonded weapon and some Sorcerer abilities just never get used.
Finally, for all the times they get to buff before combat there are times when they are caught flat-footed and they enter combat with only their daily buffs.
It all depends on our (the group's) intel.
The DM doesn't "allow" or "disallow" pre-buffing. He doesn't handle it at all in fact, we do.
If we see a fight coming we'll buff for it. Alot of times we buff as the fight goes on. (for example- all the melee holding actions prior to getting hasted).
If we *know* a certain fight is coming (say for example we know Dragon X is on the menu soon) we'll have spells prepared and get ready before we fight him.
I think its important for neither side to metagame. The DM shouldn't just "decide" the PC's have been buffing long enough, nor should the players take advantage of the fact that the DM couldn't figure out an effective way to hide part of the map from them prior to their *characters* opening the door.
(not that skill checks are beyond the pale for NPC's- but there should be rolls made. Whether that means the PC's get no "pre-buff" or four hours to choose what to cast should be decided on by the dice or the actions of the people in the world.)
-S