Gamers of a certain age probably remember paging through dog-eared copies of GamePro and other monthly magazines to discover the numerous hidden characters and secrets embedded in the highly popular Mortal Kombat games. There's at least one Mortal Kombat secret that never made the pages of those magazines, however. It's a secret that was just recently revealed after over 20 years of secrecy.

The "EJB menus" (named for series co-creator Ed J. Boon) have been sitting unknown and unloved in the first three Mortal Kombat arcade cabinets since their release in the early '90s. They weren't known to the public at large until last October, when the code-crawlers at the invaluable Cutting Room Floor website revealed their existence. The menus are getting widespread attention now, thanks to a long-winded video demonstrating the unlock method on real arcade hardware, which involves quickly tapping both players' block buttons in a precise sequences. (The codes also work on MAME, where they can be simplified with some XML hacking.)

The options in the menus themselves are mainly devoted to diagnostic testing and internal management for arcade owners, but you can also use the menus to jump directly to the endings for specific characters, cheat your initials into the high score screen, and view some secret thank-you messages from Boon himself. In Ultimate Mortal Kombat 3, you can also use the menu to view a quick fatality demonstration and play a punishing, hidden Galaga-style shoot-'em-up.

Boon has said in the past that there were still undiscovered secrets in early Mortal Kombat games, and this discovery proves that he wasn't just blowing Smoke. Now, the question becomes whether there are still additional secrets to be found in addition to these newly uncovered menus. Boon wasn't immediately available to respond to a request for comment, but we'll provide an update if he lets us know how to unlock a playable Goro in the original Mortal Kombat or something.

Update: On at least some Ultimate Mortal Kombat 3 cabinets, the EJB menu trick can also be used to set the cabinet to free play mode, letting you (and anyone else) grab a game without putting in any quarters, as shown in this video. Given that, it's probably a good thing for arcade owners everywhere that this trick remained secret for so long.