Atticus's Amulet is a magical necklace made mostly out of Iron that grants Atticus O'Sullivan a number of abilities, boasts his magic beyond a normal druids, and renders him immune to most kinds of direct magical effects without detracting from his own ability to use magic. Since it is bound to his aura, it cannot be removed by force, and makes his mere touch instantly fatal to faeries, as though his body were made of cold iron.
It is unknown just what time during his 2,100 year of life Atticus made the amulet, he mentioned the whole process of making and binding it to his aura took about 750 years. He later made similar amulets for The Morrigan and Granuaile.
While the Cold Iron medallion of the amulet is what provides Atticus's with his legendary protection from magic without disrupting his own, the charms around it provide magical "short cuts" for Atticus's most common spells, allowing him to cast instantly.
- Bear Charm acts as a kind of "magic battery" which Atticus can draw on when he is not directly connected to the earth. It must be charged when he reconnects.
- Camouflage Charm cloaks Atticus and anyone he's in contact with in a near invisibility.
- Faerie Specs Charm which provides him the ability to see into the magical spectrum, making things such as enchantments and auras visible
- Healing Charm In case Atticus needs to heal himself or another quickly, the Healing charm allows him to cast the spell instantly, by still requires magical energy to spend.
- Night Charm which provides night vision.
- Shapeshifting Charms to allow Atticus to shapeshift into his 4 forms: a hound, a stag, an otter, or an owl. These forms were chosen by the earth when Atticus was bound to the earth during his Tattooing. It's shown on the book cover that each creature has its own charm for this. The amulet changes size when he shapeshifts so that it always "fits" in whatever form he is in.
- "Soulcatcher" Charm is first mentioned in Tricked (Book 4) as an experimental charm Atticus conceived in 1812. It's supposed to "catch his soul" if he dies and hold it to his body while triggering automatic healing of the wound, then restore a his mind (which is backed up every five minutes). Naturally he had no way to test it, but it appears to have worked during the events of Hunted when he was shot in the head by a sniper.
- Vampire Charm while not fully created yet, Atticus has mentioned several times that creating a charm to easily unbind Vampires (which are undead and therefore not protected by the laws of Druidic magic) would be a very good idea. He tested it unsuccessfully in Trapped, where it appeared to have no effect other than startling the vampire he was fighting, but after Atticus spoke the unbinding spell normally, the vampire violently exploded rather than "melt" like they normally do.
- Fulgurite Stone Back Not a proper "charm" per se, but rather a supplemental amulet given to Atticus by Perun. It renders the wearer immune to lightning strikes.