We have been working our way through the AH LCG game starting with the base set. By the time we got to the Dunwich campaign we had it's base set and four of the expansions waiting for us. We started with new characters and incorporated all the new cards, including the expansions, into the pool of cards available. As the Dunwich expansions came out we simply added and used them too.
We haven't yet finished Dunwich (just about to start Essex County Express), are we able to add the Carcosa cards into the mix and use them before we start that campaign? Is that going to cause balance issues with the Dunwich campaign? Is it meant to be played stand alone added to just the base cards?