The "MK series" refers to a popular line of fighting video games developed by Midway Games, now known as NetherRealm Studios. The series debuted in 1992 with the release of Mortal Kombat, which became famous for its unique characters, engaging storylines, and signature finishing moves called "Fatalities." Over the years, the MK series has expanded to include numerous sequels, spin-offs, and adaptations in various media, including movies and animated series. The games are known for their competitive gameplay, diverse character roster, and iconic elements like the Kombat system, which emphasizes skill and strategy in battles.