This was a little weird, but maybe this has happend to you too. Ok, in the desert map with the giant skeleton, and I think a few basilisks (and, IIRC, there's a hostile adventuring party near the head of the skeleton), I rested after taking out some insanely hard hard enemy (probably a Greater Basilisk), I rested. Everything went well. Well, after resting, I decided to leave the map, but decided to take a longer look at that skeleton (just so dang interesting). Well, waiting for me instead of the usual 5 Gnolls that usually random spawn, was 30 (believe me, I paused and counted). The was no dialogue, so it wasn't a planned encounter by programmers. I personally think that 5 of the usual random spawnings stacked. Has this happened to anyone else. If you've got more info, let me know.

lol, that's nuts. Of course, you still would have slaughtered all of them.

Yes, it has happened to me but in the High Hedge area. The enemies consisted of a boat load of skeletons (about 20), 15 hobgoblins, and about 10 war dogs -- all at one time.

Oh, yeah, of course I slaghtered them. Nice pile of useless equipment left over too. Yeah, the High Hedge was bad about large numbers of enemies. But I think that is because the random spawning points are so close together. I'd get the enemies on the run, just to run into twice as many trying to kill them. The worst battle I on that map ever fought was with the Flinds right below the tower thing. 8 flinds, 2 loads of skeletons, and 10 Gnolls. NOt fun at all. And i really didn't get much out of it, except a lot of gems and a little gold.

On Werewolf island, the werewolfes kept respawning in 1 place - 30 or so at 1 spot. Fireball and they were all gone... but kept respawning. o.o

It is a bug

IIRC it occours when you load in an area - a new set of monsters will spawn at each spawning-point. Multiple loads = even more enemies.

For me it usually happens in the Firewine Ruins (kobold commandoes , Ouch)