Johnny Cage is a character in the Mortal Kombat fighting game franchise by Midway Games and NetherRealm Studios. Introduced in the original 1992 game, he is an action movie star with an extensive martial arts background. The series depicts Cage as one of the primary heroes defending Earthrealm from various threats, as well as the comic foil. In the rebooted timeline, Cage is also the love interest to Special Forces officer Sonya Blade and the father of their daughter Cassie. He is inspired by martial arts star Jean-Claude Van Damme, particularly Van Damme's character, Frank Dux, in the 1988 film Bloodsport. A staple of the franchise, Cage has appeared in various media outside of the games.

Liu Kang is a fictional character and the main protagonist in the Mortal Kombat fighting game franchise by Midway Games and NetherRealm Studios. Depicted as Earthrealm's greatest warrior and champion, he debuted in the original 1992 game as a Shaolin monk with special moves, which were intended to be the easiest for players to perform. Since his introduction, Liu Kang has appeared as playable in every main installment except Mortal Kombat: Deadly Alliance (2002). He is also one of the protagonists of the action-adventure spin-off Mortal Kombat: Shaolin Monks (2005).