Plan a potluck dish assignment.
A potluck fails in one of two ways: not enough food, or seven desserts and no main. Both are solved by calculating dishes rather than volume. Start from servings needed — guests plus a buffer of about 25%, because people take more at a buffet than they would if plated — and divide by the servings a typical shared dish provides, around eight. Then check the two ratios. Dishes per course tells you how many of each category to assign, and dishes per contributor tells you whether one dish each is enough or whether some people need to bring two. Assigning courses explicitly is the only reliable fix for the dessert problem.
Potluck Planner
Servings needed = guests x (1 + buffer%); dishes = servings / servings per dish, rounded up, at least one per course; per contributor = dishes / bringers
About four, based on 30 servings needed at eight servings per dish. With ten contributors that means some bring a dish and others bring drinks, bread or supplies.
Assign courses rather than inviting people to bring what they like. Give each contributor a category — main, side, salad, dessert — and confirm before the day.