This character is in charge of a platoon of Marines, under the Marine Corps Commanding Officer (CO-MC). The 1st platoon CO is also assigned the ancillary duties as the CO-MC's executive officer.

The Platoon Commander is responsible for his platoon and any other duties assigned. The integrity and readiness of the platoon are his foremost priorites. The Platoon Commander finds himself working primarily on military matters but also has the responsibility to contribute to base defense as a whole, relying on the Chief of Security and his department to handle the day-to-day policing of the starbase facility that are not military-related.

When assigned by the CO-MC, this individual also has to deal with civilian issues aboard the starbase, working in coordination with station security to bolster and/or replace security forces, manpower for investigation and crowd control, and facility security normally outside the Marine charter.

The CO-MP reports directly to the Marine Corps Commanding Officer, and the Starbase Commander in turn. Marines assigned to the support vessel (USS Patton) are under the authority of the ship's commander in the absence of the Marine Corps Commanding Officer.

This is a leadership position and can be featured in almost all missions involving conflict or security in or in the vicinity of the starbase.