The original reason Scorpion and Sub-Zero came along was because when we were driving around Chicago looking for props to create these characters and costumes, we found a costume shop in Chicago and they had a ninja-like costume. We took pieces of this, pieces of that, and made a mask for this, and came up with this yellow ninja. That character didn't have a name at the time. We knew that in the arcade games, the amount of memory that you could use was put in EPROM—chips, basically. Memory was very, very scarce, so if you add more memory to your game, your game costs that much more, and then it costs the company that much more. A lot of attention went into the economics of it, and so we knew that if we could take a character and change their color and use basically the same memory to create two characters, we'd save a lot of money and we'd have two characters.
We colored the yellow ninja blue and created this blue ninja. We're giving them moves and everything, and blue looked like ice, so that gave the theme of Sub-Zero and freezing people. Yellow looked like fire, and that was like the Scorpion thing. They were opposites of each other, and that prompted the story behind them being these opposing ninja-clan-type characters. Everything rolled off of that.