Classic video games tended to hold some happy secrets, sometimes in the forms of easter eggs or developer menus. These were usually uncovered during the games’ heydays, but Mortal Kombat, Mortal Kombat II, and Mortal Kombat III’ s Ed Boon menus, also known as EJB menus, have only just been discovered. Pressing the player one and two block buttons in certain patterns in each game makes the menus appear.
Here’s a video from YourMKArcadeSource that shows how to enter the codes to access the secret menus in all three Mortal Kombat games.
The Mortal Kombat secret menus are included as a means of allowing developers and arcade owners easy access to certain game elements. You can run diagnostic tests, game audits, check coin book keeping, or enter initials. There are a few special inclusions. The first two games each have a “Hello” section with shoutouts. All three games have an option to view all character endings.
Mortal Kombat III is most fun, though. In addition to the character endings and testing stuff, it also has an option to enable hidden characters, like Smoke. Plus, there’s a Galaga -inspired Penacho/Miller minigame.
If you’re somewhere with one of these three Mortal Kombat arcade games, see if your timing is good enough to pull off the codes. The code for the first game is 1P block x5, 2P block x10, 1P block x2, 2P block, 1P block x2, 2P block x3, then 1P block x4. The second game’s code is 1P block x5, 2P block x10, 1P block x2, 2P block x8, then 1P block x2. Finally, the code for both Mortal Kombat III and Ultimate Mortal Kombat III is 1P block x5, 2P block x10, 1P block x3, 2P block, 1P block x2, 2P block x2, 1P block x3, and 2P block x3.
Source: YourMKArcadeSource