These staves, weighing only 3 lb (1.4 kg) were willowy and hollow. However, they were made entirely of glass, which appeared to have been strengthened to become as tough as oak.
Staves of defense allowed their wielders to cast the mage armor and shield spells without expending their personal repertoire of memorized spells. Instead, the staves themselves would lose charges, depending on the spell used (one for mage armor, two for shield). Only those that had the ability to cast these spells ordinarily, i.e., without use of the staves, were able to make use of the staves' abilities, once they were attuned to it.
In total, these staves had ten charges, which could be recharged (from halfway to fully) during a short period of downtime. However, every time the staff was depleted, it had a 5% chance of shattering, rendering it useless.
As well as the spellcasting potential, the staves would infer a small improvement to the casters' armor.