Are kids automatically invited?

No. Not unless it says "Mr. and Mrs. Smith and family". If it says "Mr. and Mrs. Smith" then that does not mean the child is invited.

Is this everyone else's understanding as well?

No, there are a couple ways to cue if you're inviting the child or not. Indicating on the RSVP card how many seats are reserved is one, as well as how the envelope is addressed (i.e. addressing it to just the couple is inviting the couple, addressing it to "the x family" invites the family).

Depends on how the invitation is addressed.

"Mr. and Mrs. X" = only the couple is invited

"The X Family" = kids are included too

No, unless you use the word "family". Don't do that if you don't want the family. Invite people by name.

Is it okay NOT to include the kids?? And if I invite the children of some ppl, do I have to invite everyones children?

That's where it gets more murky. From what I've seen, inviting the children of close family members but no one else is perfectly acceptable, but it gets hairy when you're picking and choosing kids of friends. Including newborns is also an acceptable exception.

It's perfectly acceptable to have an adult only wedding, we're doing 21+ only. Just keep in mind some guests may not be able to attend if you don't invite their children, and you need to be okay with that. ETA: We chose to stick firmly to 21+ only because my family is extremely touchy and it would still cause tons of drama that I just wanted to avoid. But it is totally acceptable to invite in circles, or not at all.

We are only inviting family kids. I'm hoping my friends will get the whole "Mr. and Mrs. Smith" does not include their kids.

Of course it's fine not to include kids, but your invites need to reflect that. The invitation should be addressed to the exact people you want to attend.

Nope. I'll have a few kids (who are in the wedding but that's it.

Not unless my child's name is on the invite too. If it's just addressed to FH and I, I start finding a babysitter.

I am wording them exactly who is invited. (On the envelope). But I have a few friends I could totally see not getting that.

@Miranda- Something else you could do is on the RSVP card have a line that says something like "____ seats reserved in your honor" and fill in the blank so they know. Or they have one that's more "___ out of ___ seats" where you fill out the second blank and they fill out the first.

Only people from out of state are allowed to bring their kids to my wedding. I am addressing it as "Mr and Mrs" and then in the RSVP i am putting "we have reserved ____ seats in your honor". If its family and they have three kids I say 5 seats in your honor, if i only want the couple it's 2.

Hopefully you don't mind if I jump in here with a question, OP! If you are inviting the whole family and they have more than one child (under 18), is it okay to put the Smith family/The Smiths versus writing out all names?

We're doing 21+ with the exception of family. Our invitations are addressed to the specific people invited, rather than families. ETA @Smidge, that's what we're doing (family, not all the names).

It is not rude nor necessary to invite kids. Just make sure you properly address invites to only the adults. Also, I think it's fine to invite some kids and not others. I'm only allowing close family and the bridal party to bring their children. Don't stress over it!

So I already have my rsvp cards all printed out without the "we have reserved _ seats in your honor " thing. Could I add a insert to the invite saying that? Since it's not on the rsvp card?