Mortal Kombat · Sega Genesis · 1993
Entering ABACABB on the Code of Honor screen re-enables all blood and fatalities that were censored from the Genesis port by default.
The Genesis version of Mortal Kombat shipped in 1993 with its blood removed and the most graphic fatalities altered by default. A hidden code restored the uncensored content for players who wanted it; its letters, ABACABB, are a nod to Abacab, an album by the band Genesis. The SNES version had no equivalent code and shipped permanently censored. The resulting public outcry over the difference between versions, amplified by the code's widespread circulation in gaming magazines and on school playgrounds, directly contributed to the formation of the Entertainment Software Rating Board (ESRB) in 1994.
From the main menu, select "Code of Honor." Enter the sequence A, B, A, C, A, B, B. A chime will confirm the code is active. Blood and uncensored fatalities will now be enabled for the entire session.