- Utility:
- Requirement: 5 woods.
- Notes: Wooden Jamb required. Doors can be destroyed by melee weapons.
Upgrade 1 (F6): Bronze Door
- Utility: Stronger that wooden door
- Requirement: 5 woods + 15 Bronze ingots
- Notes: Wooden Jamb upgraded required. Doors can be destroyed by bronze/steel weapons (and siege)
Upgrade 3 (F6): Steel Door
- Utility: Stronger that bronze door
- Requirement: 50 Steel ingots
- Notes: Wooden Jamb upgraded required. Doors can be destroyed by steel weapons only (and siege)