Hard Enough finding a Cast...Now I have to find Understudies?

Okay, so you know that Secret Society the Stage Play is my first production! So I'm a novice. I don't know everything there is to know yet! And I damn sure didn't know that once you pour all your blood, sweat, and tears into finding the perfect cast, you have to turn around and find the perfect back-up cast! Yes! They're called understudies and they must be just as good and just as ready as the main stars because God forbid something happens to a cast member--especially a key player! That would mean the production will not happen!  So in case, you have understudies who have practiced as much and as hard as the cast. And they are able to fill the role if something happens to the main member. It makes sense, yes, but it also makes me have a headache!

So now, we're on the prowl for understudies. I'll be damned!