Skill Effective Range
When the skill is used, only targets within the effective range will be damaged
I.E: Both side has 3 squads, friendly and enemy.

The Rear Guard of the friendly side uses a skill with the targeting type of "Random enemy target", then:
If the effective range is 5, the effective range is the entire enemy formation, where 1 target within the 3 squads will be chosen at random.
If the effective range is 4, only the enemy pioneer and backbone will be targeted。
if the effective range is 3, only the enemy pioneer will be targeted。