My Roman cavalry AND a BG of hastati essentially charged a BG of Spanish cavalry at the same time. We basically played it wrong at the time and I want to show what we should have done.
The situation is this - the Spanish cavalry was facing away from the Roman cavalry. They used their move (being undrilled) to turn around 180 degrees while stationary. This kept them in charge range of the Roman cavalry and hastati.
The situation - Spanish cavalry under threat from two sides
The way we played it initially was that the Roman cavalry charge included a wheel to bring them into base to base contact with the Spanish. But we staggered the hastati charge meaning that two bases contacted the Spanish horse - which did not move to conform to the charge (as it should have).
This is wrong! The Spanish rear base should turn to face.
Page 55 of the rulebook states that the hastati can instigate a flank attack as no part of their BG was in front of any part of the Spanish BG and the first part contacted was the side / rear corner of the target base. And the hastati could wheel as they started > 1MU from the Spanish.
What we should have done. The rearmost base turns to face.
The Spanish should have dropped one cohesion level immediately (we didn't play it that way!). We also should have turned the base(s) contacted to face the flank attack. As the hastati only contacted the rear right base, the front right base could continue to face the Roman cavalry.
As a consequence, the hastati impact on a ++ POA regardless. As the Spanish are Disrupted, the conflict should play out differently.
In the original combat, we had it that the two bases of front rank hastati contacted the Spanish horse (giving them 4 dice to 2). This should not have happened. It should be 2 dice each at impact for the horse facing the hastati (with the hastati at ++) and 4 dice each for the Spanish and Roman cavalry in contact (with no POA).
The Spanish are Disrupted and so lose 1 dice in 3. The Spanish have 6 dice in total so we'll have it that they will take 2 off the front battle (against the Roman cavalry). Russ' commander is nearby.
So - the hastati have 2 dice vs 2 dice at ++. They roll 4,4 for 2 hits, the Spanish roll 5,1 for 1. Being Superior, they re-roll the 1 for a 2 - just the one hit. So it's Romans 2, Spanish 1.
In the front impact its 4 Roman dice vs 2 (see above). There are no net POA's for this impact - it's a straight roll. The Romans roll 5,3,2,2 - the Spanish 4,2. 1 hit each but overall the Romans take it 3 to 2. The Spanish must make a cohesion test (at -1 for Disrupted) - the commander being near takes it back to a straight throw. They make it with a 7 and stay disrupted. The Death Roll means a 4 or greater is needed - they get a 3 (fail) and lose a front rank base.
The Spanish lose a front rank base - so the rear base must move forward to conform.
The BG's then conform for the melee. The hastati now have an overlap on the Spanish rear. Being disrupted the Spanish lose 1 dice in 3 - they decide to take it off the rear rank so the hastati have a 'free' bash. They have 4 dice to 0 with a POA for better armour (so the Spanish - if they had a throw - would need 5 or 6 to hit). The Romans bash in with 6,6,3,2 - 2 hits.
For the battle at the front, the Romans have 4 dice to 2. They have a net POA for better armour but the Spanish are Superior. Russ fought his commander in the front rank for this round - therefore they become Elite. The Roman cavalry score just 1 hit (6,2,2,1) and the Spanish respond with 1,2 - but can re-roll both and get 3,1 - no hits. So the Spanish lose 3-0. The Cohesion test is at -1 and the commander cannot influence as he is in the front rank. The Death Roll is 4 or more. The Spanish roll 10 for cohesion - a pass! But they lose another base from the front rank.
Another base lost - the game is up!
The Spanish now look doomed. They don't lose a dice this round for Disruption (as they have < 3 bases) and decide to split them.
The hastati get 4 dice to 1, as do the Roman cavalry. The hastati get 5,3,1,1 - the two re-rolls deliver no hits and the Spanish fail to hit. Romans 1-0 here. The cavalry step in with 6,5,4,2 to the Spanish 1 - re-rolled to a 6. So the Romans win 4-1. The cohesion test and death roll come up with a 4 and a 4. Another base lost and the Spanish automatically break and are removed.
Summary
That seemed to work better. The Spanish did put up a fight but looked doomed from the start. Being Disrupted as a result of the flank attack put them on the back foot immediately and the hastati hitting at ++ started the decline. In the way we played it the first time, the Spanish actually won the impact - but that was because we didn't apply the Disrupted element.
So - a lesson learned and proof that sometimes the best way to learn the rules is to stick some troops on the table and just play it out.
The lesson from the battle - don't allow flank attacks unless its impossible to avoid. They are devastating.