Wade Watts

Wade Watts, known as Parzival in the OASIS, is the main protagonist of Ready Player One. He is a gunter: someone who hunts for Halliday's Easter Egg. Wade is eighteen years old at the start of the novel, describing himself as "an overweight teenager with acne." In the OASIS, his avatar "is a mirror image of him, but taller, skinnier, and with less teenage acne." Wade is the first gunter to find the Copper Key, the first step to acquiring Halliday's Easter Egg.
AECH

Aech is Wade's best friend, and a fellow gunter. Aech and Wade know each other only through the OASIS, but spend a lot of time together. As Ready Player One goes on, Aech and Wade spend less and less time together, due in part to their efforts to get the egg.
James Halliday

James Halliday, known as Anorak in the OASIS, is the creator of the OASIS. With his death, he left his fortune hidden somewhere in the massive world of the OASIS in the form of a video game Easter Egg. Due to the Easter egg, most gunters know nearly everything about Halliday, due in part to his journal, Anorak's Almanac, being released upon his death. He was a very lonely man, and lived the last fifteen years of his life in seclusion.
The Sixers

The Sixers are the main antagonists in Ready Player One. The Sixers are people working for Innovative Online Industries, or IOI. All of their usernames in the OASIS start with the number six, which is how they got their nickname. The Sixers want to be the first to find Halliday's Easter Egg to turn the OASIS into an expensive simulation for massive profit.
ART3MIS

Art3mis is a popular female gunter who keeps a blog of her quest for Halliday's Easter Egg. She discovers the area to get the Copper Key before Wade, but Wade still gets the key first. Later on in Ready Player One, Wade and Art3mis are in a romantic relationship.
Daito and Shoto

Daito and Shoto, two brothers from Japan, are the fourth and fifth to find the Copper Key. They are gunters whose avatars appear as traditional samurai. Further into Ready Player One, Shoto is much more important than Daito.