So, I'm building a quest which can begin for the player in two ways: finding a letter or talking to a particular npc. In the Condition Item sub-box in the Topic Info window of the dialogue editor I notice there is a check box for "OR." In order for the line to fire for 1) the right speaker, AND 2) possessing the letter OR 3) having talked to the other NPC, do I need to have 1 AND, 2 OR, 3 AND, or 1 AND, 2 OR, 3 OR, or 1 AND 2 OR 1 AND 3 or is it better to just make a duplicate entry for condition 2 and 3 (that is, one topic with 1 + 2 as conditions and a second topic with 1 + 3)?

OK, let me rephrase: that's kind of confusing above. I have another case: I have three conditions. I want the dialogue to fire 1) if the speaker is a particular Npc AND it is either a Thursday or a Saturday (the days don't matter, I just wanted to add some randomness.) So here's how I have it set up in the line dialogue editor:

GetDayOfWeek NONE == 4 OR
GetDayOfWeek NONE == 6 OR
GetIsID Actor:"QutNPCElric" == 1 AND

What makes me think this is set up wrong is that the line is showing up for other actors in the filtered dialogue editor. So, it seems to be treating the ActorID line as an OR, as I read it. Anyone figured out how to do something like this?

Ugh, nevermind. I love it when I answer my own question minutes after I ask it. I just found the arrows to change the order of the conditions. Moving the AND condition to the top of the list seems to fix the problem. Hope this helps someone down the line

Yes it does, thank you.