A ballista is a massive crossbow that fires heavy bolts. Before it can be fired, it must be loaded and aimed. It takes one action to load the weapon, one action to aim it, and one action to fire it.

Ballista
Siege Equipment
Attributes
Ballista
Size
Very large (1x2m)
Armor Class
15
Hit Points
50
Damage Immunities
Poison, psychic
Description
A ballista is a massive crossbow that fires heavy bolts. Before it can be fired, it must be loaded and aimed. It takes one action to load the weapon, one action to aim it, and one action to fire it.
Bolt.
Ranged weapon attack: +6 to hit, range 24/96m, one target. Hit: 16 (3d10) piercing damage.