Here is a rule we have been trying…
Engaged Land Combat:
The attacker has 3 options after each round of combat;
continue the battle, 2) retreat, 3) partial retreat, or 4 ) stand. Options 3 and 4 end further combat by the attacker, and allow the defender a one-time only play of any of these 3 actions; retreat, stand, and/or counterattack. Defending unit retreats follow the same retreat rules as attacker except the destination territory is any that is under friendly control. Counterattacking units get one round free combat using attack dice. Defending air units must retreat and cannot counterattack. After the counterattack, the counterattacking units are considered engaged and cannot be moved on their turn and must become the attacker. Attacking or defending units that stand and are still in a territory that contains unfriendly units on their turn, must either attack and/or move to territories that were in friendly control or had friendly units at the start of the their turn.