Deterioration is the gradual loss of the hit points of certain items. An item is anything that can be hauled by a colonist. Deterioration is akin to an item taking damage from projectiles, explosions, or fire since they all affect the same hit points stat. Affected items include clothing, armor, weapons, and most resources. Deterioration is applied to an item on the ground that is not under a roof. A shelf provides protection for any item. Whether the item is indoors or outdoors does not matter, therefore a roofed room without a door still provides protection. Mountains have an indestructible roof making them well-suited to protect perishable items.
When an item's hit points reaches 0 it is destroyed.
- Deterioration is also applied to apparel (armor and clothing) when worn. A colonist wearing any apparel with hit points 20% or below will get the 'Wearing tattered apparel' thought. A colonist wearing any apparel with hit points between 21% and 50% will get the 'Wearing frayed apparel' thought.
- Artillery shells that deteriorate to 0 hit points will explode.
- Raw food deteriorates in addition to still being prone to spoilage.
- Equipped weapons do not deteriorate.
- As an item loses hit points it also loses it's market value very quickly. Items lose other stats as well:
- Apparel suffers lowered armor protection and insulation.
- Ranged weapons suffer lowered accuracy.
- Melee weapons suffer lowered melee damage.
- Personal shields suffer lowered max energy and lowered recharge rate.
An item's deterioration rate specifies how many hit points are lost per day. Depending on the type of item it ranges from 0.25/d to 10.0/d. This stat is listed in an item's information tab. If this stat is not listed, or listed as '0.00/d', then the item will not deteriorate. Rain greatly affects deterioration rate. For items with the quality stat, a high quality item will have a lower deterioration rate than a poor quality item.