+1 Combat Result if your unit is fighting the enemy unit's flank.

Fighting a foe in its flank is a great advantage. The enemy warriors cannot easily turn to combat their attackers, and the sudden appearance of an enemy from an unexpected quarter has a psychological value all of its own. Therefore, if your unit is fighting the enemy in its flank, it receives +1 Combat Result. Remember that if your unit has two or more ranks of at least five models, it's likely to disrupt the enemy formation into the bargain as well (see Disruption, below).