Ok I hope this isn't something I missed in the rules since we just got the game. But sometimes the rules say to put cards challenges at the bottom of the deck and othertimes in a discard pile. What do you guys do? I was thinking a discard pile that got reshuffled when full would make more sense but I would be curious if there is an official rule on this.

Thanks

I've always had the cards put on the bottom of the deck, and can't recall ever having to reshuffle at all.

As an aside, I also split my now large market deck, thanks to expansions, into two decks, and keep the cards rotated by reshuffling the two decks after each game and creating two new decks. Helps keep the same cards from popping up all the time.