Just need a quick confirmation on the expansion sets. You ONLY play against the encounter deck provided with that particular set. However, you may tweek your Hero deck with any/all cards available (from all sets), providing you follow the deck building rules. Correct?

No, you also mix in cards from the big box expansions. ( core set for mirkwood and khazad dum for dwarodwelf )

Thanks for the information. So if I read your reply correct, all the Encounter cards for all 6 Adventure Packs for Mirkwood and Core Set can be combined if the icons are require?. If that is correct, next question is….IS IT REQUIRED? (i.e. If I have purchase "Conflict at Carrock" do I combine the encounter cards from "The Hunt for Gollum and the Core set? and so on with each additional Mirkwood Adventure Pack?). Sorry if I am making this confusing. I have not purchased any additional sets as of yet, except I did buy Khazad Dum.

Not exactly. What you do is look at the icons on the quest cards. The big icon is the icon for that pack. The other two (or three) icons are the other encounter sets you need to add to the deck. And yes, it is required. Hope that helps.

I would check out page 26 of the core rulebook. Compare the symbols listed there to the symbols on 1A of each quest. Now look at those same symbols on the AP cards to know which sets to include. Also, the instructions for each AP should list specifically which sets are included for each scenario.