Boulder

Ammunition for the Catapult Turret

The Boulder is what the Catapult Turret throws in ARK: Survival Evolved and ARK: Survival Ascended: a spiked rock that deals heavy damage from a distance. The description leaves no doubt about where it goes: "Can only be used in a Catapult Turret." The ARK Wiki confirms that, for now, no other turret can launch it.

Made inside the turret

No engram is needed. Boulders are crafted in the Catapult Turret itself; each one takes 5 seconds and gives 0.05 XP, from:

• 30 Stone
• 3 Metal Ingot or Scrap Metal Ingot

Finished boulders can be taken out again to store them or to move them to another turret. One weighs 1.5 and a stack holds 100, so a full stack weighs 150. Loot adds more: 36 crate types can contain boulders, among them the easy, medium and hard crates of the Bulbdog Fetch and Circuit Chase missions on Genesis Part 2. Our records list the item on 14 maps.

Damage against stone

The wiki puts a number on it. Each Boulder that hits a stone-tier structure does 700 damage, against 10,000 hit points for that tier. A single hit therefore takes 7% off a stone wall, and 15 boulders bring one down.

Catapult or ballista

The wiki compares the Boulder with the Spear Bolt fired from a Ballista Turret. In its favor, the boulder costs much less, so it is a quick and cheap way to wreck structures from range, and its high arc lets it drop over walls onto whatever stands behind them. Against it: catapults are much harder to aim, every boulder is used up when fired, and the sustained damage is lower. The Spear Bolt suits accurate direct fire, while boulders make strong long-range artillery against buildings. A friend who watches where shots land makes aiming easier; raise or lower the firing angle when a shot falls short or flies too far.