Scenario Attacker/Defender (The Scenario Defender is the side that sets up wholly or partly on-board and does not have to capture terrain (on other than its setup boards) in order to fulfill its Victory Conditions, while facing an opposing side that enters wholly from Offboard. This latter side is termed the Scenario Attacker. The Scenario Defender and Attacker both exist or neither does; a scenario cannot have one without having the other. In scenarios where neither exists, the use of rules pertaining specifically to their respective roles is not allowed)