There are two ranking systems in Halo 5: Guardians: Spartan Rank, a progression ranking system, and Competitive Skill Rank, a skill ranking system.
A player's Spartan Rank (SR) is displayed on their player card. Players start at SR-1 and finish at SR-152. They rank up by earning XP through completing multiplayer matches and completing commendations. As a player ranks up, he unlocks a rank-specific REQ Pack.
Competitive Skill RankEdit
Competitive Skill Rank (CSR) measures a player's skill in a playlist. The first ten matches a player completes in a playlist are "placement matches," which evaluate a player's individual performance and place them in one of seven tiers:
Once a player has been assigned a tier, winning or losing is the only way to rank up or down, respectively. For Bronze through Diamond, there are six levels within each tier. If a player continues to win after reaching the sixth level of a tier, they will move up into the next tier. However, players will never move down a tier by losing. Onyx tier does not have six levels and instead shows a player's raw Elo score. Players in the Champion tier are one of the top 200 players in that playlist.
A player's CSR will reset every season, but a player's pre-season rank will be available to see on their service record. There are specific rewards for every season that are awarded through the REQ system.