Setting up and Epic Game

By MechSpike, in Arkham Horror Second Edition

So my friends and I decided to set up an epic game with every expansion on the table. We want it to be 8 investigators, and possibly Azathoth as the AO. What I need to know is exactly how to do this. Mixing in every card from every expansion seems silly to me because that's way too many cards and half the cards will not to see the light of day. What I've been doing is making 60 card decks for mythos/other world/common/unique etc etc all the decks pretty much. This way I get a good mix of everything and it's not too bulky. I was also thinking about taking mythos cards and possibly encounter cards and splitting them up so I'll have one of each expansion in a pile of 7 cards. Then take several of these piles of cards and shuffle them individually, then place them on top of each other to create a mythos deck. Therefore we will automatically get one of each expansion in a random order every 7 turns. Sure once we hit say turn 6 we will know what expansion to expect next, but even so that will hardly give us an upper hand since 4 of those expansions all open gates in Arkham. Any other suggestions for doing such a game? Usually when playing with more than one expansion you never run into any of the different features that go along with the expansions, let alone having all 7 in play. I'm sure some of you have done such an endeavor but what would be the best most compact way of doing this...