A potluck is a gathering of people where each person is expected to bring a dish of food to be shared among the group. Synonyms include: potluck dinner, Jacob's join, Jacob's supper, faith supper, covered dish supper, pitch-in, carry-in, bring-a-plate.
Folk etymology has derived the term "potluck" from the Native American custom of potlatch; the word "potluck", however, is actually of English origin. It is a portmanteau word formed from (cooking) pot and lucke. The earliest written citation is from 1592: "That that pure sanguine complexion of yours may never be famisht with pot lucke," Thomas Nashe. As this shows, the original meaning was "food given away to guests", probably derived from "whatever food one is lucky enough to find in the pot", i.e. whatever food happens to be available, especially when offered to a guest. By extension, a more general meaning is "whatever is available in a particular circumstance or at a particular time."
Potluck dinners are often organized by religious or community groups, since they simplify the meal planning and distribute the costs among the participants. Smaller, more informal get-togethers with distributed food preparation may also be called potlucks. The only traditional rule is that each dish be large enough to be shared among a good portion (but not necessarily all) of the anticipated guests. In some cases each participant agrees ahead of time to bring a single course, and the result is a multi-course meal. Guests may bring in any form of food, ranging from the main course to desserts.
Another variation on the potluck dinner is the rota meal. Participants take turns providing food for the entire group, rather than each participant bringing a dish. For regular meals with a fairly consistent set of participants, this dramatically reduces the amount of preparation effort required.
Another variation, popular in America, is the Traveling Dinner (or Progressive Supper). Each course of a meal is served at different homes. For example the appetizer is served in the first home, the entree in the second home, and the dessert in the last home. The number of courses can be expanded depending on the number of guests. Some groups may choose to have a Reverse Progressive Dinner where the diners eat the courses backwards. A constraining factor of the traveling potluck is Drinking and Driving. Groups have opted to manage this by limiting the guest list to neighbors within walking distance, a designated driver, or limiting alcohol consumption. Another strategy has been for groups to hire a limo for the evening.