|Artwork of Proto Man using the Proto Buster from a preview image in the Mega Man Archie Comics series.|
The Proto Buster is Proto Man's signature default weapon. The Proto Buster can fire small singular projectiles that move in a straight line, passing through terrain. These projectiles can automatically be charged, to the same effect as the Mega Buster's Mega Man 4 variant. Unlike the Mega Buster however, Proto Man can only have two Proto Buster projectiles on screen at the same time, or one single charged projectile. In addition, the Charge Shot cannot be disabled nor modified, unlike Mega Man's.
Proto Man has a different position from Mega Man or Bass to shoot, and as a result the pellets fired from the Proto Buster are slightly lower than those fired from the other Buster weapons. This can help Proto Man to defeat or stun enemies that normally are too small for the basic buster shot.
Unlike its appearance in Mega Man 9 and Mega Man 10, the charge is not lost when Proto Man gets hit.
The option to use the Proto Strike from Mega Man Powered Up can be enabled and disabled from the level settings menu - if enabled, regular shots from the Proto Buster will take a larger shape similar to the Mega Man 6 charged shot, with the damage being ramped up to normal charge shot damage (3) as opposed to regular damage (1). Unlike its version from Mega Man Powered Up, the Proto Strike in Mega Man Maker cannot deflect shields or act as armor-piercing.
The limit of two shots onscreen of the regular Proto Buster extends to the Proto Strike.
- Proto Strike first debuted in the game Mega Man: The Power Battle, as a melee ranged buster attack, functioning significantly differently than Proto Strike's appearance in Mega Man Powered Up.