You magically seal the cracks, crevices, gaps, and breaches of a room or vehicle, protecting those inside it. You must be in a room, structure, vehicle, or chamber with a ceiling, walls, and windows, doors, portcullises, or other ways of physically closing off ingress and egress, or the spell fails. When you cast this spell, you touch the floor of a chamber that is up to fifty 5-foot squares and up to 10 feet tall, shaped as you desire. You can ward a long hallway, a square bedchamber, the lowest deck of a ship, the interior of a siege engine, or a similar chamber. Until the spell ends, the chamber is protected in the following ways.   Barred. Doors, windows, and other entryways into the chamber are magically locked, as if sealed by an arcane lock spell.   Bolstered. The chamber’s walls, floor, ceiling, doors, windows, and similar structural features are immune to nonmagical bludgeoning, piercing, and slashing damage and have resistance to magical damage.   Impermeable. Magical and nonmagical water, gases, and other liquids and vapors can’t pass into the chamber from outside of it. Safe. The air within the chamber is safe to breathe and capable of sustaining any number of breathing creatures for the duration, provided the creature is wholly within the chamber.