Recently I just started the War of the Golden Skull (Defending) with a party of three level 13 characters and though the first fight was tough, I finished it on my second try and leveled up to 14 as I expected. Then, I noticed my group would level up after every encounter and I would just steamroll through the fights leveling up. I decided to stop leveling up once I hit level 18 at the Hommlet castle. So the question is if I keep leveling will content that I haven't done (Such as the Slave Traders, Monster Mash) be no longer challenging, or are those quests still difficult at level 20? I've never played through those quests before and I'd hate to ruin the experience by devastating any opponents I face. Just for reference, the content I haven't done is basically everything in Verbobonc besides the Drows and White Dragons.
The Slavers are never easy, level 20 or no. Monster Mash depends entirely on how quickly you put down the (spoiler): Spoiler clerics . I could say the same for the drow. Generally, I'd say tactics count for more than levels in all the quests you name.
With a party of three, most, if not all of the quests mentioned will be at least considered challenging even at level 20. If your not careful your party of three could become a party of two right from the start with the slavers, how ... not gonna say, just make sure you save before you approach them.
After beating the slavers I think I'll just keep my group at 18 until the Demigods quest. I guess tactics>levels was right.
