As part of each unit’s weapon attack declaration, players can twist the torsos of their 'Mechs (except for four-legged 'Mechs, which cannot torso twist) or rotate the turrets of any turreted vehicles. This twist or rotation lasts for the remainder of the turn, affecting firing arcs for the Weapon Attack and Physical Attack phases. The torso or turret returns to its forward position in the End Phase.

’Mechs: A 'Mech can twist its torso one hexside (60 degrees) to the left or right of the direction in which its feet are pointing.
This new alignment modifies a 'Mech's upper body firing arc as described in Firing Arcs, but for movement and hit location purposes the 'Mech is still considered to be facing in its pre-twist direction.

Vehicles: Vehicles with turrets may align the turrets to any hexside. Rotating its turret modifies a vehicle's firing arc as described in Firing Arcs.