A staff is a shaft, usually of wood, that is typically as tall as or slightly taller than its wielder. Staffs are sometimes crowned with decorative crystals or other symbols of magical power.
This implement also counts as a quarterstaff. Even a creature who doesn’t have proficiency with the staff as an implement can use it as a weapon, but if the staff is magical, the creature cannot use its properties or powers, only its enhancement bonus and critical hit effect.
Published in Rules Compendium, page(s) 274.