Some quests allow the OL to place reinforcements at the start of his turn. Fat Goblin explicitly states that you can activate them on the turn they were placed. None of the other quests where reinforcements are places at the start of turn state this. Also, no where in the rules does it state that monsters don't activate when reinforced at the start of turn. So my question is this, do monsters that are placed at the start of turn activate on that turn for all the quests like Fat Goblin or not?

Based on the steps of an OL turn, I would say yes since the figure is there before the "activate monster groups" step takes place so it would be allowed to activate. Also, I think that is the reasoning for allowing monsters to reinforce at the start of turn instead of end of turn. I'm pretty sure this is the correct answer but would like outside input to verify my logic.

Your reasoning seems sound. If the monsters are on the board before the "activate monsters" step, then they would be activated along with all the others.

I agree with wootersl, and it is how we have played the game. We have played multiple campaigns, and have been through nearly all of the quests. It would appear that the quests have been written by multiple people, which has led to certain assumptions being made.

Although the quests within the quest guide follow a general template, often times certain information is left out, when it is clearly stated in other quests. What you have found is a good example. Another one is that some quests explicitly state that the heroes begin on the entrance tiles. Other quests don't say anything. Normally, this wouldn't be a big deal, since even the rule book states that they "generally" start on the entrance tile.

The problem comes in with several quests that have you explicitly starting in the middle of rooms, or one quest which actually states that "… the heroes MAY start on the pond tile", but doesn't offer any other alternatives (although one assumes the alternative is the entrance tile).

It is little things like this which has plagued Descent e1 and its expansions in the past.

The quest guide seems to use a template when providing key information (headings being the same for things like "Special …", "Reinforcements", "Victory Conditions", etc. It would be nice if they would actually complete the template and spell out all information in all quests consistently, even if it seems obvious. I think this would elimiante a fair amount of FAQ questions.