In QFG3 there are some events that are time based, happen on certain specific days. Mainly the big issue is if you don't do everything in the city, after a certain time they close the gates, and you can't get back in. If you need certain items (such as a dispell potion), you are out of luck. This in general should lead to not so good endings, in the game.
Also there are is one character you could miss talking to in the city, in the Inn. One of the members of the Lost City expedition. After a while he dies/killed. I can't remember if some of the stuff he tells you is 100% required or simply will lower your score.
There is the thief character in the city, that you have to befriend to get best end game situation. Although he may still show up no matter what. I'm not sure if he leads to a dead end, but befriending him helps with some other events. He appears at night on completely different days for each character class. For example magic user he might appear on day 7, and fighter he might appear on day 14, and thief he might appear on day 12. These examples aren't accurate, i'm just giving an analogous example.
Likewise I think there is monkey you can befriend, but if you don't do it, it might mess things up.
But most things lead to less points, not necessarily a total dead end.
Post edited May 17, 2012 by Baggins