The Masterbolt

The Masterbolt is Zeus's weapon, which is shaped like a lightning bolt. It is very effective, and can kill. Zeus uses it for battles and lightning.

History
In The Lightning Thief, Zeus's Masterbolt was stolen. Hades was accused of stealing it, then later Percy Jackson was accused. So Percy went on a quest so no one would be unfairly accused, to find that Ares was associated with the crime. When he goes to Hades, Percy finds that Hades's Helm of Darkness was stolen as well. Also, the backpack Percy was given would have the Masterbolt inside it, as soon as he got close to Hades. Later, it is revealed that Luke Castellan actually stole the Masterbolt when he took some of the demigods on a field trip to a council. Ares was indeed associated, but he was recruited by Luke. Luckily, the Masterbolt was safely returned to Zeus!