Depends on your style of play. I'm generally pretty slow, so it took me around 70 hours or so. I imagine most people would get through it in 40 or less though.

thank you

Depends on which campaign we're talking about, what kind of character you're playing, whether you take along a henchman or not, whether you skip through dialog or not, and whether you visit all the optional areas. Particularly in the original campaign, there are some absolutely sprawling labyrinths that are completely optional. I'm just going to step through this mentally:

For the original campaign (5.5-15 hours):
chapter 1: 90-240 minutes
chapter 2 (part 1): 60-240 minutes
chapter 2 (part 2): 60-120 minutes
chapter 3: 90-240 minutes
chapter 4: 30-60 minutes

For Shadows of Undrendtide (4.5-8.5 hours)
chapter 1: 90-180 minutes
chapter 2: 90-150 minutes
chapter 3: 90-180 minutes

For Hordes of the Underdark (5.5-14 hours)
chapter 1: 90-180 minutes
chapter 2: 120-300 minutes
chapter 3: 120-360 minutes

So about 16-40 hours total.



edit Heh, I guess then I'm on the faster side of things. If my high end is 40 and your low end is 40, then that's probably a good medium.

Ad 5 hours at least to the longest time for every chapter for me because I want to find every item and speak to every person and see every nook and cranny

This is all very good info.