Delayed fatality —

Decades later, players are still unlocking secrets in classic Mortal Kombat

Ed Boon's arcade diagnostic menus have remained hidden since the early '90s.

Kyle Orland - Feb 24, 2016 4:18 pm UTC

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.

Promoted Comments

UserIDAlreadyInUseArs Praetorian
jump to post

Pokrface wrote:
The menus seem mostly given over to items arcade owners would care about—coin audits, hardware testing, etc. Were these menus not documented in the owner's manual for the cabinets? And if not, why the hell not? And was there not a simple switch inside the cab the owners could flip to get to them, rather than having to enter some absurd tap sequence?

I was a cabinet tech a long time ago, and yeah, most of that was available through DIP switches. I know I never had to tap buttons to access any of the administrative features on a Mortal Kombat cabinet for any reason, ever. This looks to me like more like a feature to test these things were working without the devs needing a physical board handy to do so until the very end when the system was ready to be burnt and shipped, and let's throw in a few extra things, too, what the hell because programmers are programmers everywhere.

402 posts | registered May 15, 2013
XkeeperSmack-Fu Master, in training
jump to post

Oh, hi. (I run TCRF.)

The EJB menu isn't the same as the service menu you can normally access if you have access to the service button. The linked articles describe which of the options are identical between menus, but there are some unique and expanded options in the EJB menus. The added audits are things that seem to specifically check hardware/software issues instead of in-game data, possibly useful for testing or debugging when doing repairs.

The menu could also be useful as a hidden code like Pac-Man's; bootleggers might manage to convert the graphics and audio to some other title, but would be quickly outed if they didn't catch and remove this obscure code.

Personally, I'm wondering if ol' Boon has anything to say on the subject of remaining secrets...

Aurich wrote:
Silly pork face, you align CRTs with manual controls inside the cab, not the software.

Also, while this is totally true, many arcade games still offered features to help the process. It's a lot easier to align a crosshatch than it is a constantly-changing game field, after all.

2 posts | registered Feb 28, 2012
parasyteArs Praetorian
jump to post

Megabeard wrote:
I suppose it fits quite well into the story of the demise of arcades that the game which perhaps best represented the end of accessibility of popular arcade games to casual gamers had a secret menu that was so inaccessible that no one found it until long after the death of the arcade itself.

Tons of games have secrets that aren't found or are only found 10+ years later. There are a lot of ways to hide a code and without its existence being leaked somehow, often by the developer, not so many easy ways to find a way to enter the code.

Just by way of example, in the SNES game Shadowrun a debug room was hidden in the released version of the game. It went undiscovered for 20 years until one of the developers mentioned it in an interview. An item obtainable there and the Winter CES string used in the debug room had been found by dataminers and thought unused (actually, the Dog Food was suspected to have been part of the Dog Items quest). Likely the debug room would never have been found if the developer hadn't said anything about it.

550 posts | registered Oct 9, 2012
LrdDimwitArs Centurion
jump to post

Pokrface wrote:
The menus seem mostly given over to items arcade owners would care about—coin audits, hardware testing, etc. Were these menus not documented in the owner's manual for the cabinets? And if not, why the hell not? And was there not a simple switch inside the cab the owners could flip to get to them, rather than having to enter some absurd tap sequence?

My college had an intro-to-CS course for freshmen where they would ask alumni to come give a one-hour talk on what being a software engineer was really like. Ed Boon came one week.

One of the thing he talked about was some hidden menus in Mortal Kombat that would make the cart flash the credits. He indicated that they were added as a business decision to combat counterfeiting; cheap knockoff makers would take the game, strip out all the normal credits, slap their own logo on it, leave everything else the same, and call it like 'Deadly Struggle'. Midway would sue, and these guys would insist that everything was all theirs. So then they would have Ed enter the super-secret code, and another credits sequence would pop up, and their lawyers would ask "So then how do you explain this?"

I guess that would be these menus. So no, these menus would not be documented, but (as others have noted) the features contained within them are probably accessible in other ways.

272 posts | registered Feb 17, 2011

Promoted Comments

UserIDAlreadyInUseArs Praetorian
jump to post

Pokrface wrote:
The menus seem mostly given over to items arcade owners would care about—coin audits, hardware testing, etc. Were these menus not documented in the owner's manual for the cabinets? And if not, why the hell not? And was there not a simple switch inside the cab the owners could flip to get to them, rather than having to enter some absurd tap sequence?

I was a cabinet tech a long time ago, and yeah, most of that was available through DIP switches. I know I never had to tap buttons to access any of the administrative features on a Mortal Kombat cabinet for any reason, ever. This looks to me like more like a feature to test these things were working without the devs needing a physical board handy to do so until the very end when the system was ready to be burnt and shipped, and let's throw in a few extra things, too, what the hell because programmers are programmers everywhere.

402 posts | registered May 15, 2013
XkeeperSmack-Fu Master, in training
jump to post

Oh, hi. (I run TCRF.)

The EJB menu isn't the same as the service menu you can normally access if you have access to the service button. The linked articles describe which of the options are identical between menus, but there are some unique and expanded options in the EJB menus. The added audits are things that seem to specifically check hardware/software issues instead of in-game data, possibly useful for testing or debugging when doing repairs.

The menu could also be useful as a hidden code like Pac-Man's; bootleggers might manage to convert the graphics and audio to some other title, but would be quickly outed if they didn't catch and remove this obscure code.

Personally, I'm wondering if ol' Boon has anything to say on the subject of remaining secrets...

Aurich wrote:
Silly pork face, you align CRTs with manual controls inside the cab, not the software.

Also, while this is totally true, many arcade games still offered features to help the process. It's a lot easier to align a crosshatch than it is a constantly-changing game field, after all.

2 posts | registered Feb 28, 2012
parasyteArs Praetorian
jump to post

Megabeard wrote:
I suppose it fits quite well into the story of the demise of arcades that the game which perhaps best represented the end of accessibility of popular arcade games to casual gamers had a secret menu that was so inaccessible that no one found it until long after the death of the arcade itself.

Tons of games have secrets that aren't found or are only found 10+ years later. There are a lot of ways to hide a code and without its existence being leaked somehow, often by the developer, not so many easy ways to find a way to enter the code.

Just by way of example, in the SNES game Shadowrun a debug room was hidden in the released version of the game. It went undiscovered for 20 years until one of the developers mentioned it in an interview. An item obtainable there and the Winter CES string used in the debug room had been found by dataminers and thought unused (actually, the Dog Food was suspected to have been part of the Dog Items quest). Likely the debug room would never have been found if the developer hadn't said anything about it.

550 posts | registered Oct 9, 2012
LrdDimwitArs Centurion
jump to post

Pokrface wrote:
The menus seem mostly given over to items arcade owners would care about—coin audits, hardware testing, etc. Were these menus not documented in the owner's manual for the cabinets? And if not, why the hell not? And was there not a simple switch inside the cab the owners could flip to get to them, rather than having to enter some absurd tap sequence?

My college had an intro-to-CS course for freshmen where they would ask alumni to come give a one-hour talk on what being a software engineer was really like. Ed Boon came one week.

One of the thing he talked about was some hidden menus in Mortal Kombat that would make the cart flash the credits. He indicated that they were added as a business decision to combat counterfeiting; cheap knockoff makers would take the game, strip out all the normal credits, slap their own logo on it, leave everything else the same, and call it like 'Deadly Struggle'. Midway would sue, and these guys would insist that everything was all theirs. So then they would have Ed enter the super-secret code, and another credits sequence would pop up, and their lawyers would ask "So then how do you explain this?"

I guess that would be these menus. So no, these menus would not be documented, but (as others have noted) the features contained within them are probably accessible in other ways.

272 posts | registered Feb 17, 2011

Kyle Orland Kyle Orland has been the Senior Gaming Editor at Ars Technica since 2012, writing primarily about the business, tech, and culture behind video games. He has journalism and computer science degrees from University of Maryland. He once wrote a whole book about Minesweeper.

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