Port-A-Diner

Port-A-Diners are world objects found in Fallout 4 and Fallout 76.

Characteristics
Port-A-Diners are automated vending machines, promoting an "authentic dining experience", that retrieve food from a carousel and place it on a conveyor belt to the customer. This machines dot the ruins of Boston and Appalachia, and while most of their food has rotted away, a single perfectly preserved pie rests in the middle, although it is very difficult for the machine to actually grab and deliver it.

Chance
The chance for a port-a-diner to succeed depends on the player's Luck stat and the the number of times the machine has been activated. When used, a randomly generated number between 1 and 1000 is picked. That random number and the two previous values combine to generate the chance for getting a pie. When the relation below is true, the machine is successful:
 * $$2\times \text{Luck}+\frac{\text{Attempts}}{2}\leq \text{Random}$$

Locations

 * One is found inside the Dugout Inn, in Diamond City.