Mortal Kombat has an unusual story behind its origins and history.
Mortal Kombat was always a big game, even though Midway didn't intend it that way. It was dark and foreboding, bloody and brutal; therefore, it was a hit. What began as a "filler" title in between larger sports titles, Mortal Kombat became the series that made Midway relevant in the gaming industry, and a major player in the fighting game genre for decades to come.
Mortal Kombat was not meant to be based around a Bruce Lee clone, as the character Liu Kang might have indicated. It was originally planned to be based around Johnny Cage, who if you know his very first move list, you might guess what major actor he was based on. Johnny Cage was meant to be the central character, based on Jean-Claude Van Damme. That was why the actor playing the actual role, Daniel Pesina, had a move where he did the splits and jabbed his opponent in the nads.
In what may be pure coincidence, a game released later on based on the movie Street Fighter actually did star Jean-Claude Van Damme as Guile. However, the game and the film were both so bad that it never became a serious issue why he may not have let Midway base Mortal Kombat around him.
In the end, the very first Mortal Kombat ended up making Liu Kang the star, as reflected in the special-effects-laden movie starring Robin Shou.
Mortal Kombat brought something new to the fighting game genre as well, as now you needed to use a specified Block button to deflect incoming attacks. This became almost the defining trait of the series from then on. Where other fighting games had you holding the joystick or control pad away from the opponent, Mortal Kombat gave you the option to block whenever you wanted to.
Another staple of the Mortal Kombat franchise grew from the developers having a "what if" session. In Street Fighter II, when you used a projectile attack and it hit another one, they canceled each other out. Mortal Kombat's developers dared to ask, "what if the projectiles actually went right past each other?" Hence, when you use a projectile attack in Mortal Kombat, the opponent has to block, jump, or take full damage. This was also the reason the character Sub-Zero had a distinct advantage over the rest. If his ice attack hit you, you were frozen in place until either he attacked you again or the effect wore off, giving him a free attack if you weren't careful.
Something else you may not have known is that many of the characters in Mortal Kombat and MK2 were all acted out by the same person. Daniel Pesina was the man behind the mask of Scorpion and Sub-Zero (using a palette-swap art technique), as well as Johnny Cage. He reprised these roles, as well as the then-playable character Reptile and the new hidden character Smoke in MK2. Liu Kang was played by Ho-Sung Pak, a Korean-American who also played his rival, the sorcerer Shang Tsung in the first Mortal Kombat.
It wasn't until Mortal Kombat 4 that Midway switched digitized images for motion captured characters, attempting a new 3D fighting system and losing almost all of the fans in the process. The next three games in the series, Mortal Kombat V though VII (subtitled Deadly Alliance, Deception, and Armageddon) succeeded in bringing back some of the fans. Mortal Kombat vs DC Universe tried to do the crossover that Capcom had been doing successfully for years, and the fans once again looked elsewhere as it failed. It wasn't until Midway became NetherRealm Studios and rebooted the series that Mortal Kombat won most of its fans back.
What do you think of the not-so-well-known origins and history of Mortal Kombat?