That would be a “no host” dinner. You could offer appetizers, soft drinks, wine or beer and then have guests pay for their main dinner. Throw in cake or dessert as the host. Depending upon the amount of people and how close these people are to you could just call them.
So you would say,
“We are organizing a party for John at La Casita Restaurant, Wednesday, October 14 at 6 p.m.
6-7 Cocktail hour (Appetizers served)
7-9 No Host Dinner
9-1 Celebratory Dessert
Call to let us know:
Something like that…If you are not providing anything like appetizers and dessert I would not call it an invitation. The word Invitation denotes that the host is treating to something.
That sort of gathering would only need a postcard saying, “We are gathering for a Dutch Treat dinner to celebrate John’s birthday.” Date, Time, etc. and phone number to call to RSVP Yes or No.
You are better off spending less money on invitations and decorations, etc. and treat folks to coffee and dessert (for those who do not want to have dinner). Just say, “How Lucky Can I Get?” “As a birthday gift and wish I would love to have you bring me a scratch-off ticket. I’ll split my winnings with you!”
That is a lot of fun and it is a good way to minimize the guest’s anxiety about “not” bringing a gift. That is always a little uncomfortable for some.
I think it is fine to ask guests to pay their way. You will have organized the event for them and are creating the day to bring people together. On the invitations explain the activities for the day and say that you would love them to be there with the family but to enable the day to be a success each guest will need to pay for their ticket and this is required by to enable the cruise staff to prepare for the numbers attending. It isn’t tacky at all. If guests do not want to pay then they will be missing out.
First, you won’t call it an “invitation” or use the words “invited,” since you are requesting payment. It needs to be an “announcement.”
You would call it a “no host” or “Dutch treat” event.
“We’d like to announce that we are honoring “who ever” at a Dutch Treat dinner on date and time, at place.”
Include the reservation card for dinner with prices and selections…when they return it you know how many people will be there.
I advise against having people let you know and then pay at the door. You will likely run into a problem with people not showing up and you have reserved/confirmed a dinner that you will have to pay for.
The best and most correct plan, however, is to invite all guests to a celebration which includes cake, coffee, champagne, etc. at an hour after dinner like 8:30 and includes a card for those who want to come at 6:00 and pay for their dinner. That way you give everyone a true invitation and opportunity to come and be with you to honor your father-in-law. At 8:30 with the full crowd, you can do special tributes and presentations, etc. Tables are set for dinner guests and extra tables for dessert only guests.