Hello,
I just noticed this when reading the Battlemech Manual, but it appears to be a reproduction of an unclear rule from Total Warfare. Using BMM pages, on pp22 when determining LOS for attack declarations, if LOS lies directly along the edge between two hexes, the defender gets to declare which "side" of the path is used, and mentions that this can also affect attack direction.
However on pp32 the rule is simply that if the attack direction crossed an intersection between two zone's hexsides, the target chooses which side is hit by the attack before the hit location roll.
This is unclear to me - we've always been playing as though the LOS rule takes precedence, and whichever side of the line is chosen on attack declaration also determines which zone is hit (and if the initial defender returned fire and also hit a zone intersection, that attack and hit direction would be bound by their original declaration)
If the rule in Attack declaration is followed explicitly on its own, it could cause some strange effects like a target getting the benefit of terrain from the attack declaration but avoiding rear hits by then pushing the damage to the other side of the line, and it could also result in two mechs firing at each other resolving damage on two different sides of the line. Is this the intent, or does the LOS determination in attack declaration always also determine the attack direction?
