Reinforced Walls: These are masonry walls with iron bars on one or both sides of the wall, or placed within the wall to strengthen it. The hardness of a reinforced wall remains the same, but its hit points are doubled and the Strength check DC to break through it is increased by 10.
Iron Walls: These walls are placed within dungeons around important places such as vaults.
Paper Walls: Paper walls are the opposite of iron walls, placed as screens to block line of sight but nothing more.
Wooden Walls: Wooden walls often exist as recent additions to older dungeons, used to create animal pens, storage bins, or just to make a number of smaller rooms out of a larger one.
Magically Treated Walls: These walls are stronger than average, with a greater hardness, more hit points, and a higher break DC. Magic can usually double the hardness and hit points and can add up to 20 to the break DC. A magically treated wall also gains a saving throw against spells that could affect it, with the save bonus equaling 2 + one-half the caster level of the magic reinforcing the wall. Creating a magic wall requires the Craft Wondrous Item feat and the expenditure of 1,500 gp for each 10 foot-by-10-foot wall section.
Walls with Arrow Slits: Walls with arrow slits can be made of any durable material but are most commonly masonry, hewn stone, or wood. Such a wall allows defenders to fire arrows or crossbow bolts at intruders from behind the safety of the wall. Archers behind arrow slits have improved cover that gives them a +8 bonus to Armor Class, a +4 bonus on Reflex saves, and the benefits of the improved evasion class feature.