Basic Artillery: gives control of the ballista to the hero, allowing one shot with a 50% chance to inflict double damage.
Advanced Artillery: gives control of the ballista to the hero, allowing two shots with a 75% chance to inflict double damage.
Expert Artillery: gives control of the ballista to the hero, allowing two shots which inflict double damage.
Artillery is a secondary skill that gives the hero manual control over the Ballista. Basic Artillery provides a 50% chance that attacks from a ballista deal double damage. For advanced Artillery this is a 75% chance and for expert Artillery a 100% chance. Advanced and expert Artillery also allow the ballista to shoot twice per round, instead of once. When a hero with Artillery defends during a siege, the player gains manual control over the arrow towers.
Though not the worst skill, Artillery is of limited use. Whereas it may be useful early on in the game, at least on resource-poor maps of impossible difficulty, later on it usually provides considerably less bonus damage to a hero's army than do secondary skills such as Offense or Archery (see Figure 1). Moreover, given that a ballista has only 250 health and acts last during the combat round, it may be destroyed in battles even before it can inflict any significant damage. Another disadvantage of Artillery is that the ballista is not deployed when attacking creature banks or defending against a siege. However, the control that Artillery provides over arrow towers in sieges can be quite valuable, also because it enables the defending hero to cast the first or last spell in each round.
Figure 1: Required Number of Ranged Units for Archery to Deal More Damage than Artillery Does as a Function of Hero’s Attack and Skill Level.