Green Lanterns act as galactic police officers whose job it is to serve and protect all life in their sector. Each Green Lantern wears a ring that grants them a variety of powers. The effectiveness of the ring is tied to the wearer’s willpower. A Green Lantern with strong willpower will best a weaker-willed Lantern in a duel. Anything which weakens the Green Lantern’s mind, such as a telepathic attack, may render his ring useless.
Hal Jordan is the most well-known Green Lantern. He was the first human ever inducted into the Green Lantern Corps. Hal Jordan’s name is mentioned in conversations about possibly being the greatest Green Lantern of all time. He is also a founding member of the Justice League of America.