Another concept introduced in this game is the "Kombat Kode". A Kombat Kode is a six-symbol code entered at the VS screen in a two-player game to modify gameplay, fight hidden characters or display certain text messages. Also introduced in this game was the "Ultimate Kombat Kode", a 10-character code using symbols, that could be entered on the game over screen after the continue screen disappears in single player mode. It was used to unlock a robotic version of the character Smoke; it can be done by either the player or the arcade operator. The arcade owner could reset this code by accessing the game's diagnostic menu by resetting to the factory settings within the "MK3" cabinet (except in version 2.1, which can only be done by accessing the EJB menu). The codes were revealed through gaming magazines, promotional material, and other "Mortal Kombat" media.