The Service Branches of the Commonwealth Armed Forces (CAF) are each distinct and separate, and there is an obvious rivalry among them. While this might seem bad on the surface, this unity of one branch against another helps to bleed off what might otherwise arise as racial tension among the different species.
- The Royal Army handles planetary assaults and garrison duty.
- The Royal Navy deals with space battles, transport and support of ground troops.
- The Royal Marines, a small, elite force, specializing in ship-to-ship boarding actions and quick assaults of ground targets like a spaceport or industrial complex. (Army troopers note that if you can't walk and chew gum at the same time, you end up in the Marines because there you don't have to walk.)
- The Royal Aerospace Force handles fighters in ground actions or garrison duty; fighters carried on Navy vessels have their chain of command hooked into that of the Navy.
- The Special Forces units of the CAF handle all anti-terrorist activities in the Commonwealth and foster terrorist activities in TOG space. Their efficacy at getting supplies to the Renegade Underground has been hailed as one of the greatest reasons for the Underground's success.
- Each Planetary Militia is composed of natives to that world and is responsible for its defense. They also help out during emergencies: vast floods, life-threatening storms, and the like. Often, a militia's officer corps is totally filled with retired CAF officers. Militia troops are also trained to become guerrillas if their world is overrun, and serve as special advisers to Marine and Army units active on their world.
Sky Marshals are selected from among the leadership of the CAF to administer vast fronts in the battle with TOG. This is more than a ceremonial position, and its responsibilities have broken more than one commander. While they have been likened to Overlords, this analogy is not accurate. Perhaps better would be a comparison to an Imperial Warlord appointed for duty in a specific County or Dukedom.
The Republican Army and Naval Forces exiled in the Commonwealth are a fully separate military working under its own authority. Although they have common goals and have formed several Joint Commissions to accommodate a dual military structure, both militaries maintain operational independence, forming joint commands only for specific operations.