I have a question about the PACG and I'll use rise of the runelords as an example.
When moving on from Burnt Offerings to the Skinsaw Murders do you remove all the cards from burnt offerings and add in skinsaw murders or do you just add the skinsaw murders.?
If you just keep adding the new cards by the time you get to spires of Xin-Shalast the decks will be pretty big diluting the Xin-Shalast encounters with stuff from the previous 5 adventures.
You just keep adding.
But if you read the Adventure Path, you'll see that it says to start removing basic cards and then elite cards at certain points, so the dilution isn't terrible.
By the rules, you continue adding without removing the previous adventures' cards.
You do not remove any cards from the box/game unless otherwise stated.
Do take note of the special instructions on the Rise of the Runelords Adventure Path Card, though, as it covers the 'otherwise stated' bit.
It discusses a particular way for card removal completely to use later in the adventure path.