If adventurers are looking for an automated means by which they can defend their base camp from monsters in Valheim, then the Ballista might be the perfect solution. This Misc Structure serves as an AI-controlled turret that fires up to 20 projectiles at enemy targets. The damage dealt for each shot depends on the type of missile loaded into the Ballista. For reference, Wooden Missiles will deal 75 points of damage when striking an opponent, while Black Metal Missiles deal 120 damage each, 60% more than the wooden variants. Whatever the case, these devices can be practical when solo players are attempting to hold down a fort from enemy hordes attacking from multiple angles.
Crafting the Ballista in Valheim
To craft the Ballista structure in Valheim, players will need three materials: Black Metal ×10, Yggdrasil Wood ×10, and Mechanical Springs ×3. Yggdrasil Wood can be naturally found in the open world within a specific biome, but Black Metal and Mechanical Springs require a particular workstation to be made.
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First, Yggdrasil Wood is acquired by chopping Yggdrasil Shoots, the trees that grow exclusively within the Mistlands. Players are advised to acquire Wisplights or Wisp Torches to traverse through the thick mist before attempting to procure Yggdrasil Wood. However, keep in mind that Yagluth of the Plains must first be defeated. After players have found and accessed the Mistlands, they will need a Blackmetal Axe to chop down the Yggdrasil Shoots and obtain their wood for the Ballista in Valheim.
According to the community-run Valheim Wiki, Black Metal is forged within Blast Furnace using Black Metal Scrap, a resource acquired in the Plains from Fulings, Fuling Berserkers, and Fuling Shamans. The Blast Furnace is made using an Artisan Table and requires Stone ×20, Surtling core ×5, Iron ×10, and Fine wood ×20 to be assembled. Finally, the Mechanical Springs are also made from an Artisan Table using Refined Eitr ×1 and Iron ×3. Refined Eitr is a high-end crafting material made from the Eitr Refinery, the workstation used to process Sap and Soft Tissue. Once players have acquired all three resources for making the Ballista in Valheim, they can place down the turret in a 4×4 wherever they please.
Valheim is available for PC but will release in early 2023 for Xbox One and Xbox Series X|S.
Source: Valheim Wiki