If your Army Faction is ORKS, once per battle, at the start of your Command phase, you can call a Waaagh!. If you do, until the start of your next Command phase, the Waaagh! is active for your army and:
Units from your army with this ability are eligible to declare a charge in a turn in which they Advanced.
Add 1 to the Strength and Attacks characteristics of melee weapons equipped by models from your army with this ability.
Models from your army with this ability have a 5+ invulnerable save.