Our wedding isn't going to be a formal wedding by any means. Just a simple dessert reception prepared by yours truly (as long as don't go insane before then). My question is....how do I demand guests RSVP politely? I NEED to know an amount because I have to rent chairs and tables (which adds up quickly) and of course make an appropriate amount of desserts. We will have roughly 200 invites, but since the wedding is 3 days before Christmas I know that not everyone will be able to show up. Any help from you brides and grooms out there would be great!