@jca with regards to @JLeslie ‘s comment, I wonder if the people coming to the “potluck” party didn’t actually know what “potluck” meant. The reason I’m suggesting this possibility is the fact that @JLeslie ‘s party, people were invited to a luncheon/dinner and the bosses paid for it.
A lot of people are not savvy enought these days, and there are sometimes cultural differences with some employees, so some people (even a lot of people) may not really understand what a potluck party is. Some people are just boobs, but let’s not assume that about most folks.
So the flyer should say something about the definition like: We’re having a potluck party. Definition of potluck: EVERYBODY brings a dish to share. Please use the sign-up sheet with your name to write down the dish that you will be bringing. If you don’t plan to cook, please donate$5 into the fish bowl on the reception desk and write “donation” next to your name on the sign up sheet. The donations will go toward plates, napkins and cutlery.
This should also be on the flyer—Suggestions for items: casseroles, sandwiches, chili, salads, vegetable or cheese platters, chips and dip, cakes, pies and cookies, fried chicken, cold cuts, potato or macaroni or pasta salad, enchiladas, stew, pizza, macaroni and cheese, spaghetti, scalloped or sweet potatoes, tuna or egg salad, deviled eggs, bread and cheese platter, chow mein, spring rolls, chicken wings, nuts, iced tea, punch, soda, napkins, plates, cutlery. These are just suggestions, BE CREATIVE.
Also add this to the flyer—Note: Everyone is welcome to attend, but last year a lot of people came to the party, but only a few people brought food, so there wasn’t enough for everyone. Please be considerate and bring a dish or donate $5 so that everyone can enjoy the party.
The host should definitely supply a few extra items anyway, like big bags of chips from Costco and a big cheese pizza and possibly the napkins, plates and cutlery. You can use some of the donations for extra food, you just don’t need to write that on the flyer (so you don’t have the problem of people asking about where you are ordering it from or how much it cost).
The flyer should be posted in the breakroom, on the inside of the bathroom stall doors, at the reception desk (next to the fishbowl and the sign up sheet) on the kitchen fridge, and sent out to employees about a month in advance, then two days before the party and once more the day before the party. If NONE of this works, you can assume that most of the non-participants at your job are sourpusses or selfish boobs.