Vader can move, be displaced, perform melee attacks, range attacks and be targeted by ranged attack because he is not engaged by the AT_RT. Same with the AT-RT? Correct?
The rule state that:
Quote
While a trooper unit is in a melee with another trooper unit,
those units are engaged. A unit that is engaged cannot perform
moves, cannot be displaced, cannot perform ranged attacks, and
cannot be targeted by ranged attacks.
Trooper units can be only engaged with other trooper units.
Trooper units cannot be engaged with vehicles, and vehicles
cannot be engaged with other vehicles, even if both units are
in a melee.
Thanks