When worn, armor of respiration renders you immune to all dangerous gases, whether they deal direct damage or inflict a harmful status such as confusion. This runic effect does not improve with enchantment, as it is completely effective at any enchantment level.
Invaluable armor, keep one, even leather. It allows you to easily use the dungeon’s traps against its monsters. For example, you can lead monsters through a caustic gas trap to damage them. Paralysis traps become a powerful resource as you can intentionally trigger the trap, possibly by throwing an item on the trigger, and repeatedly attacking the paralyzed monsters.
Things that stack: