Invitation wording for attire

I would put in bold letter "Please wear a costume" that way they can't miss it.

I would put on the details card that costumes are optional.

View Quoted Comment Yes I would say optional to wear costumes. Like you said not to everyone wants to dress up.

People may just not be looking closely. That sounds so fun though!

I don't think people will all dress up anyway since it's definitely not a thing everyone does.
But if it's on your invite make sure it's bolded!

You know what would be kinda cute? I don't know if it's in your budget but if you had a bunch of little dollar tree items people couldddd dress up with there like costume headbands (like devil horns) or witch hats and whatever else.

View Quoted Comment Yes that is what I was thinking of doing too!!

I would go online and get a cute e-card that is Halloween and send to everyone with Don’t forget the Masquerade/Halloween costume for the wedding! And add in a couple locations of costume shops if ppl need them( online or in store).

I would put a picture of someone from the bridal party in a costume on the invitation so people get the visual. Like I'd take a picture of my niece in devil horns and fake wings and put like "this bridesmaid is ready, are you".

"Please join us in your spookiest Halloween attire".

A lot of people will be dressed like themselves, their costume of choice, even if they do see it. Do not put it on the invitation itself. You can print it on an information sheet with the invitation, along with things like meals, and check with your venue to see if their are any limitations on costumes from their point of view. You may ask or encourage it, but do not require costumes . . . . Many venue's have limits including no candles or fires, nothing that sheds glitter, fur, etc, no fake blood ( or real for that matter😉). Also no real or fake weapons , which would include anything from a blade to a pitchfork. No lasers, no dragging parts including tails or dress trains. Every venue I ever worked at had limits. Many just say no horror , death, racial or political or religious . By the time you give a little description of what is okay, and not okay, everyone will have gotten the point. Also not if you will be in costume, not wedding traditional ( you do not have to say what costume ). I am guessing that it is not a religious ceremony?

I think including it on a details card is fine, and on your wedding website. I think regardless some people will come in regular clothes though.