Gatehouse - Roman citizens expect the freedom to come and go. That means you have to leave openings in your walls. Build gatehouses to allow traders and soldiers to pass freely without weakening the city's defenses. Fort - Base defensive legions in forts outside your city. Each fort houses horse auxiliaries, javelin auxiliaries or legionaries, assuming the city has a barracks to train them.
Soldiers gain in morale and health as long as they remain in their fort.
Forts don't require road access or labor, and it's a good thing, because they are such undesirable neighbors that you will want to locate them well outside your city. Reproduction of anything contained herein is prohibited without express written consent of Impressions Software .