When people ask about "the rules", they are asking about the details that change from casino to casino.

We know ace is worth 1 or 11, that's standard.

What we need to know is:

* how many decks?
* does the dealer hit or stand on soft 17?
* how many splits do you allow?
* when can we double? any two cards? any time? only 11?
* do you allow double after split?
* do you allow surrender?
* does the dealer peek for blackjack?
* how much does blackjack pay? 3:2 or 6:5?

Those are the variables. I'd never heard of "5 card charlie" rules until I saw it mentioned in the site chat, but if that's a thing I guess that should be mentioned in the rules too.