Characters can modify their bases with mundane and magical upgrades, which make their home a better place to live, rest, and defend.Each upgrade costs a specific amount of salvage, which cannot be modified. When the characters first get their base, they can only purchase tier 1 upgrades. Other tiers become available as the characters increase in level and spend salvage to buy into the next tier of upgrades.
Upgrades that are destroyed are lost, but replacements can be purchased. You can purchase the same upgrade more than once, purchasing a second upgrade of the same type when you do. (e.g. Purchasing the ballista upgrade twice gives a base two ballistae.)
When characters use salvage to purchase upgrades, they are actually building the upgrades from material they have found in the Mournland or trading that salvage in a place like Salvation for the materials they need to create the upgrade. The characters can decide the placement and cosmetic appearances of their upgrades. Note the placement of base upgrades on your base map. If a purchased upgrade requires a new room to be created, the characters can add interior walls to the base to create new chambers, provided the walls don’t increase the overall footprint of their base (unless an upgrade’s description says otherwise). The characters can divide an existing room with walls to create a new one, but they cannot add walls to the outside of the structure.