Battle of the River Trebia, 218 BC
Carthaginian General Hannibal Barca uses an apparent cavalry retreat across the Trebia river to lure Roman forces into a devastating ambush. The stage is set as the historical battle opens. You possess cavalry squads inside woods near the river that are already in flanking position. The key is to wait until the Roman army has advanced far enough to prevent their retreat or, more importantly, their ability to attack the cavalry flankers before your primary army can engage.
Your position is extremely advantageous. You have Cretan archers and skirmishers ready to assault approaching Roman troops. Use the archers flaming arrows. Youll be able to fire several shots before the Roman army ascends the hill toward engagement. As the Roman army closes in, advance your flanking cavalry behind the Roman forces.
Even though youve effectively flanked the Roman forces, you must still fight the smart fight. Avoid sending your cavalry against Roman spearmen unless theyre already engaged with your own infantry units. Charge your elephants in as the Romans engage and watch the bodies fly. Move in your flankers at the moment of engagement to decimate the Roman forces in a perfectly laid trap.
The Battle of Asculum, 279 BC
This historical battle between Senate and the People of Rome (SPQR) and the Seleucids is more straightforward than the previous offerings but still illustrates the most important combat concepts at the heart of Total War. The battle occurs in a large open field; theres no particular terrain advantage here or a real opportunity to perform a flank maneuver initially. Instead its wise to wait for the Seleucids to approach your position and counter the enemys move and positioning using counter units.
Separate your units into ranged, infantry, and cavalry units so you can easily target specific counters. Use the velites to bombard the approaching Seleucids upon approach. As the Seleucids charge, engage with a counter. Keep your cavalry away from the battle initially. The Seleucids possess plenty of pikemen and your cavalry wont fare well against those war elephants either.
Theres no reason to be the aggressor until the Seleucids get close. Dont get into a battle with war elephants away from your main forces. You want the battle to remain close so you can adjust units quickly to battle elephants or pikemen that might be gaining an upper hand. Obviously you want your own spearmen primarily against elephants and enemy cavalry while using your hastate and principes infantry against the Seleucid pikemen. Maneuver cavalry around enemy pikemen to strike the Seleucid missile units.
Ignore routed units initially upon retreat and shift forces to other ongoing battles. Concentrate on downing those war elephants with surrounding pikemen. Youll have plenty of opportunity to chase down surrendering units to complete the battle.
The Battle of Carrhae, 55 BC
Licinius Crassus leads a legion of the Roman Brutii army against the Parthians--but the Parthians are ready. The Parthian cavalry forces ambush the unprepared Crassus and the Brutii troops and massacre a stray Roman cavalry group. The Parthian ranged cavalry intercept and surround Crassus infantry and cavalry forces while the powerful cataphract heavy cavalry charge the trapped Roman forces.
Your Roman early legionary cohorts begin in testudo formation, which protects them against the enemy cavalry archer barrages. Note that as the opening cut scene instructs, the testudo formation also weakens their ability to perform hand-to-hand combat so remember to disengage the formation before fighting the approaching cataphracts.
You can use your cavalry units to chase off some of the enemy cavalry archer groups but you cant afford to chase them too far as youll need your cavalry as added muscle against the cataphracts. As the enemy heavy cavalry reaches your forces, envelop them with your cohorts then maneuver your cavalry behind the cataphract. Ignore the archers until youve conquered most or all of the heavy cavalry.
Chasing down the cavalry archers will still prove challenging. Eventually you can run them down with your own cavalry but if they continue to flee but not surrender then trap them by moving your infantry into the enemys path. Force all enemies to retreat or defeat them completely to win the historical battle.