Which character is the main playable hero in Halo: Combat Evolved?

Master Chief is the main playable hero in Halo: Combat Evolved.

The character's formal designation is John-117, and he is a Spartan-II supersoldier serving the United Nations Space Command. In the first Halo game, players control him as he investigates the mysterious ringworld known as Installation 04.

Master Chief is often identified by his green Mjolnir armor and sealed helmet. Although Cortana is a major supporting character and narrator, she is not the game's playable protagonist. Marcus Fenix belongs to Gears of War, while Commander Shepard is the central player character of Mass Effect.