It can be a real let down when an encounter goes downhill. I don't mean the standard run of the mill encounter but instead one which you put a bunch of work into and where really looking forward too. Maybe its one in which your awesome bad guy gets mobbed and dispatched by the players without managing to do a single thing of interest or the PCs had a magic item or trick that just blindsided you or likely a whole slew of other possibilities could explain why an encounter fell down.
Probably some of the blame falls to the DM in nearly all cases but the percentage of blame that one can lay at the DMs feet certainly can vary.
I had this situation on game night recently. I finally got a chance to run my encounter "Zombie Miner Apocalypse" (see below) but it just did not work very well. First off my theory of having a zombie fall on the control panel and cause the machine to make a racket fell through - my players fled back to the entrance to the cavern even in the midst of the fight to see if anything would show up - I had to 'abort' my game notes that said that the noise would attract the zombies because the encounter would be unbelievably lousy if the players where in a single file tunnel.
Fortunately my players eventually returned to the cavern, killed the last of the three zombies initially placed in the chamber and fiddled with the mining machine - so I pretended that fiddling with the machine was what would set off the encounter - I hate going back on my notes like this but better that then a bad encounter.
Once the zombies started to pour into the room things became exciting for a few rounds but it soon became apparent that the players could set themselves up in such a way that with the wizard laying down a cloud of daggers every round most of the zombies could not get at the PCs. Except in single file after the parties Paladin Defender and a bit after the parties cleric. We'd eventually get this situation where the zombies where just piling up waiting for their turn to move up to one of these two and get cut down.
Once the PCs figured out how to use the machine it turned out that my set up made resolving the encounter take too long considering that the excitement level had already (quickly) peaked and was now becoming just a chore. Finally the wizard player realized that he could drop a flaming sphere and really make the zombies situation hopeless. At this point I just called the encounter and said "OK you guys win - lets move on".
If I ran this encounter again I'd do a number of things differently.
- Skip the few initial zombies - depend on the players setting the encounter off by investigating the machine, walking on the metal floor might be enough to set things off.
- Move the control panel away from the machine to insure that the PCs can't use it as part of a wall to limit the space the zombies can get at them with. Make it essentially a one space 'podium' with controls on it.
- Make the area around the machine much wider so that the zombies are not so easily funneled.
- Once the controls are cracked its time to begin wrapping this encounter up. Let the PCs block a passage every turn so long as some one is working the controls.
