I've been the overlord for 4 dungeons in the base Descent game (with the same group of players) and each has followed the same format:
1. Heroes arrive and I play traps and spawn whenever possible.
2. I manage to kill 2 - 3 heroes (often the same hero 2 - 3 times).
3. Heroes get to treasure chests and gain improved items.
4. Traps and spawned monsters now have little effect; serve only to slow heroes down slightly.
5. Heroes get more treasure chests and even more improved items.
6. Heroes reach named monster lair ("boss battle") and one-shot every monster.
Ugh. Something just doesn't seem right. Last night, we played Quest 4 ("Spoiled Brat"). Despite playing Dark Charm (dropped Runewitch Astara to 3 health) and Brilliant Commander (upgraded one giant to master) just prior to the party opening the door to Area 6, they killed every monster in their first turn. Both the enhanced dragon and master giant were killed with one shot each.
It seems to me that no matter how well the heroes do throughout the rest of the dungeon, they should have real trouble with the last battle. Instead, the heroes abilities just seem to ramp up so much that - once they make it half-way through the dungeon - they are basically guaranteed a victory.
Is this the way the game normally plays? Do I have to defeat the heroes in the first 2-3 areas in order to win?
Other than house rules or rewriting the quest (add 30 health and 20 armor to the boss monsters), I'd really welcome any tips on making the final battle(s) more of a threat to the heroes.