The typical prize game scenario
1) The safe and the object symbolizing the prize in it are placed to a clearly visible, central location typically in a physical point of sale like a shop or store.
2) Customers receive a randomly selected code during their purchase.
3) Upon completion of purchase customers go to the safe and enter the code into the safe lock themselves, trying to open the safe with it.
4) If the safe opens, we have a winner, if it does not, the prize game continues.
Naturally different scenarios are also possible.