The White Oak Ash Daggers are weapons that were forged by witches as a means of subduing an Old One. If dipped in the ash of the White Oak Tree dating from the genesis of the vampire race and placed in the heart of any Old One, they'll remain dead for as long as the dagger stays in. This is unlike the White Oak Stake which will kill an Old One permanently. The daggers must be used only by humans because if wielded by a supernatural entity that refers to vampires and werewolves, the dagger will claim both lives.
- The dagger has to be dipped in the ash of the white oak tree. Then a human has to plunge it into an Old One's heart. This will kill the Old One for as long as it remains in the heart.
- The dagger must be dipped every time before it is wielded.
- It is not supposed to be wielded by demons as it would claim both lives - of the Old One as well as the demon. It is not yet known what falls under the definition of demon, but normal vampires are known to be included (the word "demon" probably refers only to vampires as the original owners).
- A definitive scene depicting what exactly happens to vampires, when they use it, has not yet been shown. However, it is possible that some vampire must have attempted to use it, which is why the writings suggest that demons mustn't use them.
- Apparently, The Old Ones themselves don't seem to be under the definition of 'demon'.
- The Spell that created The Old Ones decreed that only wood from the White Oak Tree can eradicate them. From this perspective, it would explain why Eric can safely dagger another Old One.
- It is unknown what happens if the daggers are used on normal vampires.
- It is possible that nothing happens, and they just heal once the daggers are removed, as the spell that enchanted the daggers is only known to be meant for The Old Ones.
- However, all weaknesses of the Old Ones have been generalized in normal vampires (any wood kills vampires as opposed to The Old Ones dying only off of white oak wood). Wood just temporarily disables The Old Ones. So, it is possible that the daggers would kill a vampire permanently.
- The daggers strongly resemble the seven "holy daggers" that were featured as the means to kill the Antichrist, Damien, in The Omen film series.
- Considered the first corporeal immortal and vampire, Eric is the only Old One who is permanently invulnerable to the white oak stake and white oak ash dagger; confirming that he cannot be eradicated but can feel the horrendous effects if his siblings are affected.