Missing cards from Munchkin game

[mgilpin]

Hello,

I have purchased this game for the public library I work at. Because the game will be borrowed by many people, we anticipate that cards will go missing along the way. Which cards are essential to play the game?

Thanks!

[Brf]

No one card is essential, otherwise it would difficult to play mash-ups where the deck is so large you would never see most of the cards.

[mgilpin]

Thank you!