The protagonist of the Mega Man X series is X. He is an advanced android created by Dr. Thomas Light and the central hero of the series.
X first appeared in Mega Man X, released for the Super Nintendo Entertainment System in 1993. Unlike the original Mega Man, X was designed with free will, human-like emotions, and the ability to grow and make independent moral choices. His name reflects the limitless potential represented by the mathematical variable x.
Zero and Axl are important playable allies, while Sigma is the series' principal recurring antagonist, but neither is the central protagonist. X becomes a Maverick Hunter, a defender of humans and Reploids threatened by renegade machines. His armor upgrades, wall-climbing, dashing, and copied weapons distinguish his gameplay from the original Mega Man's more straightforward abilities.