So, this blog has apparently been getting a number of visitors who found me on google while searching for content related to the Wrath of Ashardalon and Castle Ravenloft D&D Adventure System board games. Cool! What people seem to be looking for are ways to put the two games together into a singular experience, either through mixing the games together for a single delve, or through a longer, tied-together campaign. I'm going to start working on some custom homebrewed adventures using both games together, but in the mean-time, I offer up some guidelines for crafting your own.
First, start over at boardgamegeek.com. The forums there for Wrath and Ravenloft have a lot of custom goodness, from adventures and heroes to additional cards and guidelines for campaign-play. Wrath of Ashardalon, out of the box, does support "mini campaigns", which allow you to keep treasure and boons between adventures, but the heroes are still limited to 2nd level. There are a couple different offerings on the boardgamegeek.com forums on how to handle leveling up past 2nd level without breaking the game.
When mixing the games for a new experience, one thing to remember is to not just shuffle the monster decks all together and see what happens. The 30 card monster deck is key to the feel of an individual adventure. Construct your monster deck with 12 1xp monsters, 12 2xp monsters, and 6 3xp monsters. I would select one or the other of the encounter decks to use.
The treasure deck can be a little tricky. Wrath of Ashardalon treasures have prices on them, while Castle Ravenloft treasures do not. Ninjadorg (http://ratdorg.blogspot.com) has a list of suggested prices for Ravenloft treasures, which I would just go ahead and write directly onto the Ravenloft treasure cards.
One of my players biggest complaints about the D&D Adventure System games versus full-on 4e play was that he "missed the talking." The games are not designed with role-playing in mind. However, next time I'll take a look at how to add some more role-playing elements to the games, along with campaign play and leveling past 2.