The Great Repliforce War is an event that occurs in the Mega Man X game series, specifically in Mega Man X4. This tragic chapter of the Maverick Wars is brought about when the Maverick known as Sigma attempts to manipulate the General of Repliforce, warning him that the Maverick Hunters pose a potential threat. While the General dismisses Sigma, Repliforce is later held responsible when an entire city is destroyed, an act that Sigma and his agents actually committed.
The prideful commanders of Repliforce, outraged that they have been judged as Mavericks, decide to found their own independent nation free from human influence. The following coup sees Repliforce conducting widespread military operations and occupying several cities, leading to the mobilisation of the Maverick Hunters to suppress the rebellion.
Due in large part to X and Zero, most of the Repliforce units are destroyed, but the Repliforce ups the ante by assembling at the Space Port. Colonel dies in battle with the Hunters, giving Repliforce the time needed to migrate to their Final Weapon to space, where they hope to establish their own nation. X and Zero quickly invade the Final Weapon, but X's subordinates in the 17th Elite Unit are assassinated by Sigma's spy Double, who is destroyed by X while a distraught Iris perishes during a quarrel with Zero, prior to the eventual confrontation with the General himself.
It is during the fight with General that the Final Weapon is taken over by Sigma and set to fire at the Earth. Although Sigma is defeated, The Final Weapon can no longer be stopped. Finally realizing his foolishness, the General uses his own body to jam the weapon and cause its destruction, saving the Earth.
The war ends with a bittersweet victory for the Maverick Hunters and the Repliforce decimated. The Maverick Hunter commander retires out of guilt, being replaced by Signas. Months later, what remains of the Reploid Air Force is infected by the Sigma Virus during the Eurasia Crisis, along with their commander The Skiver.