Zero made his debut appearance in Mega Man X in 1993, and a cameo appearance in Mega Man 2: The Power Fighters. In the latter, Zero was revealed to have been originally created by Dr. Wily sometime during the Mega Man series. Zero works as a Maverick Hunter, a soldier in charge of defeating Mavericks, robots who turned against humanity. He plays the role as X's comrade and best friend in the X series. The two, later accompanied by Axl, fight Sigma, Vile, and other enemies throughout the series. While in the first two titles he only assists X during gameplay, he becomes an optional character in X3. In Mega Man X4, Zero is one of two playable characters, along with X. In his scenario, Zero is haunted by nightmares of a shadowy figure (implied to be Wily) awakening him and giving him orders to destroy an unknown individual, and visions of ensuing carnage. Additionally, during his scenario, Sigma reminds him of the time that he led the Maverick Hunters, and the encounter between the two that led to a vicious battle that led to Sigma punching out the crystal on Zero's helmet, leading to Sigma later becoming infected with the Maverick Virus. Depending on the story development, Zero can be fought as a boss character in Mega Man X5. In Mega Man X6, Zero is not initially present in the game since he went missing in the end of Mega Man X5 during a fight against Sigma, and he becomes an optional character depending on how the story develops throughout the game. In the spin-off title Mega Man Xtreme, he is an assistant character but becomes playable in the sequel, Mega Man Xtreme 2. He is also playable during the prologue and the last chapters from the role-playing video game Mega Man X: Command Mission.

Is it true that can you play as zero in megaman x?
no