It's a bit complicated so I can calculate the battles instead of @TrianglePanBrain if ye want. The attackers attack first, they also get a +200% bonus on their first attack. If the defenders are in a hill fort they do double damage while defending. Each legion has 1000 HP. The sides take it in turns to attack. If the attacking side has cavalry, they will attack, if they don't have cavalry they will use archers, and if they don't have archers they will use ground infantry. The defending side will defend with ground infantry. If they don't have ground infantry the archers will defend, and if they don't have archers the cavalry will defend. The stages of attack: 1. Attacking legion will inflict damage on defending legion according to its attack stat, as well as applying modifiers. 2. The defending legion will inflict damage on the attacking legion, according to its defense stat as well as applying modifiers. 3. If the defending legion has 0 hp, it will be destroyed and the attacking legion will straight away move onto it's next target. Go back to stage 1 4. If the attacking legion has 0 hp, it will be destroyed and the turn will end. Go to stage 6 5. If both sides have not run out of hp, the attacking legion will retreat. During this time, if the defender has archers they can attack the attacking legion while it is retreating, inflicting damage on it while it takes no damage itself. 6. The attackers will defend and the defenders will attack