Help with Munchkin + Expansions

[bernardopina]

I'm really new to munchkin. Just played a few times my friend's Munchkin Cthulhu and decided to buy mine.

So... instead of just buying Munchkin, I ended up buying Munchkin, Munchkin 2 AND Munchkin 3. Now I have questions about mixing them.

1) How many expansions mixed?

I've read many topics around saying that it's more usual to mix just two Munchkins (base + other one). So... Now, having 3 "sets", what do I do? If I buy the other ones in the future, what to do?

1.2) Is the game designed to work with all the expansions on the same game or is it designed to have just base and one expansion?

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I really don't know what to do regarding this expansions. The game is so awesome that I want to have it all, but I'm kinda scared that I'll buy it and end up not using them because the game works better with just one or two of them.

Please, need help on this. Thanks.