It is technically correct (although Miss Manners no longer approves of it) to invite some people to the ceremony but not to the reception , as well as vice versa (a private or very small ceremony followed by a big reception).

It sounds either like that is what these people are doing, or like there is no reception. Don't be offended if it is the former -- in that case, the reception is probably for a small group, not an "A list" for which you didn't make the cut. Also, some weddings are held at churches where, customarily, the entire congregation is invited. Obviously, the hosts can't be expected either to invite all of them to a full-meal reception or not to have one at all. You may find that the ceremony is followed by light refreshments and/or wedding cake and coffee anyway. But I'd eat first!

You asked, "What's the proper protocol for a response if there was no response card?" It is to respond, promptly, in writing, to the person/people who sent you the invitation. This is true whether you are accepting or declining, and whether or not you are invited to a reception. Actually, that is the way you are supposed to respond to any invitation. (Response cards are technically "incorrect," because supposedly they send the insulting message that people need to be prompted to respond, but I think that they are a nice courtesy to the guests and a BIG help to the hosts, who are much more likely to get those responses if they provide the cards!) The obligation to respond promptly to any invitation is the same whether or not the hosts have to give a count to a caterer or something. So write the hosts thanking them for the invitation and letting them know if you will be attending and if you will be bringing a guest.

Have a nice time at your friend's wedding.

what she said.

If the ceremony will be held at a church, you can pretty well assume that they are serving light refreshments after the ceremony for all invited guests, so they wouldn't send an RSVP.

Thanks so much for your help! I'm not offended if it turns out the reception guest list is smaller than the one for the wedding. I know how expensive weddings can be, and how much more expensive it is to have a big reception. I just wanted to know what to prepare for on that day, and you have helped me out tremendously. I really appreciate it!

It could be that the wedding will be followed by a cake and punch reception in the church hall for all those who attended the wedding. Just mail a note to the address of the wedding invitation saying that you can or cannot attend, and with whom.

You have been placed in a very delicate social situation because now you don't know if the reception/response card was accidentally omitted or you just didn't make the cut. You say you are not super close with the bride anymore, but can you ask anybody else who is going to the wedding or a close relative of the couple?

I see what you are saying, Scarlett. But I really don't think the OP has to do anything to figure it out. I think she could just dress appropriately for either scenario, eat enough before so she wouldn't be hungry if not served a meal afterward (although then she can just leave and go eat), and perhaps allow a few hours just in case she is indeed included in a full reception, whether a reception card was omitted inadvertently or the hosts just didn't include them for some reason.

But how will she know??

I don't think she has to know.

Thought I'd check back in a month down the road...

Turns out, I didn't go. A graduate school conference came up, and I couldn't pass it by. I sent my regards and gift to the couple and let it go. They did have a reception, though, with all the guests invited in the reception hall at the church. I think only light snacks were served (it was a 2:00 wedding).

The exclusion of reception information seems to be a trend these days, though. I received another invitation from friends of mine (I know both the bride and groom) and no response card or reception info was included. I've spoken with the bride and groom since I got the invite, and they excluded them for financial reasons--they were trying to save money. We're all college seniors who have, as of yet, not gotten jobs, and I think it seems easier to cut out some of the traditional etiquette that we may or may not fully understand. :)

did they exclude reception info, or did they just have a cake-and-punch reception at the church?

It it's the church reception, it would be best to add a line to the invitation itself that says "Reception to follow immediately," which for a 2:00 wedding would tell people, snacks not dinner. Because it's immediately--3pm. So no meal.
\ Including the note about the reception is traditional etiquette.

But etiquette does NOT say a B&G must have a big reception..

The first couple just had a cake and punch reception. I believe the second couple is doing the same. That being said, it seems like it would be considerably less confusing for their guests if they included a line on the invitation itself (still saving them the cost of a reception card) that said "reception immediately to follow."

I worked at Hallmark for 4 years, and in all that time of taking invitation orders, I never saw the exclusion of reception information. Only when my friends started getting married did I notice it.