A Protagonist is the main character of a game, which in this case are the Halo Games, in which a player plays as. Such protagonists are Master Chief Petty Officer of the Navy John-117, Lance Corporal "Rookie", Lieutenant SPARTAN-B312 "Noble Six", Fireteam Crimson, and Commander Palmer.
Halo trilogy, Halo 4 & Halo (Xbox One)[]

John-117, as seen in the Halo 5: Guardians teaser trailer, the main protagonist of most of the Halo series.
The main protagonist of these games is John-117. He is shown wearing MJOLNIR Mark V armor in Halo: Combat Evolved and MJOLNIR Mark VI armor in Halo 2, Halo 3 and Halo 4. A few missions in Halo 2 had the player play as Thel 'Vadam.
Halo 4's Spartan Ops allows players to control a member of Spartan Fireteam Crimson while wearing MJOLNIR GEN2.
Halo 3: ODST[]

The Rookie, the main protagonist in Halo 3: ODST.
The main protagonist of this game is The Rookie. Like the protagonists in the other Halo games, the identity of his face is not revealed. He also has yet to speak, so his voice is also unknown. He is shown wearing ODST battle armor.
Although the player has the ability to control GSgt. Edward Buck, Corporal Taylor H. "Dutch" Miles, Private First Class Michael "Mickey" Crespo, and Lance Corporal Kojo "Romeo" Agu, the game mainly focuses on The Rookie's journey to reunite with his team.
Halo: Reach[]

SPARTAN-B312 "Noble Six," the main protagonist in Halo: Reach.
The main protagonist of this game is SPARTAN-B312 aka Noble Six. Like the other two protagonists in the other Halo games and Emile-A239, the identity of his/her face has not yet been revealed.
Before the final game, Six's appearance was to look like Thom-A293, but Bungie decided to change that idea, and to allow Six's appearance to be the player's Multiplayer Spartan model.
Halo: Spartan Assault[]

SPARTAN Commander Sarah Palmer, one of two main protagonists in Halo: Spartan Assault.
Halo: Spartan Assault features two main protagonists: SPARTAN Sarah Palmer and Edward Davis. The game will represent a continued exploration of these characters, with Sarah Palmer appearing in Halo 4 and both appearing in Halo: Initiation.[1]
Halo: Infinite[]

Master Chief in Halo Infinite, the campaign protagonist.
Halo: Infinite's Campaign returns to the original protagonist of the series, John-117, as he takes the fight to the Banished on the Zeta Halo. In the multiplayer story, players take control of a customizable Spartan-IV, similar to Halo 4 & 5. Unlike the previous 343 games, your Spartan-IV is now considered to be in active duty rather than in-training, defending the Avery J. Johnson Academy of Military Science from a perpetual onslaught of Banished.
Players can also load into matches of Firefight, which will be played by your Multiplayer Spartan.

A default Spartan-IV, a vessel for customization and player immersion. Serves as the Halo: Infinite Multiplayer/Firefight protagonist.
Sources[]
- ↑ Halo Waypoint, Brian Reed Interview, "...Palmer’s in both stories, as is Edward Davis, another of the recruits we meet in INITIATION..."