Rank (Halo 4)

Spartan Rank is the primary ranking system used in Halo 4. Players are promoted after accumulating an amount of experience points (XP) through multiplayer (i.e. by playing War Games and Spartan Ops, completing Commendations and Challenges) and Forge matches. After reaching level 50, players are allowed to earn specializations.

Competitive Skill Rank, or CSR, is a secondary ranking system based on wins and losses rather then XP. It was designed to pair players with similar skills into the same match. After its launch date on April 10, 2013, players' CSRs can be seen on their Halo Waypoint stats. Each playlist features its own individual CSR running from levels 1 through 50.

Spartan Rank
Players begin their careers in the base SPARTAN-IV ranks. There are 130 ranks in total, from SR-1 to SR-130, unlocking armor permutations, Loadout equipment, tactical packages, support upgrades, visors, stances and emblems and weapon skins. After achieveing SR-50, players are able to select a specialization from the eight available. A specialization consists of a path of ten ranks, with various unlocks exclusive to that specialisation. Once the player has hit the tenth rank of the picked specialization, they can pick another; this process repeats until all specializations are completed at SR-130.

CSR
Competitive Skill Rank, or CSR, is a new system introduced to Halo 4 in April 2013 aimed to fill a similar role to the 1-50 skill rank systems seen in Halo 2 and Halo 3. CSR calculations are calculated-per playlist, with the highest CSR value for a player being the one shown on their Halo Waypoint service record.

Competitive Skill Rank is calculated in one of two ways, depending on the playlist. Several playlists use a win/loss system to determine ranking, while others utilize individual scoring, which determines rank based on the player's performance against everyone in the match, teammates included. It is also affected by the CSR's of the other players in the game: outperforming and beating players with higher CSRs will make a player more likely to rank up, and vice versa. Playlists that utilize individual scoring allow players to rank up faster than those that use team scoring.

The playlists that utilize individual scoring are:
 * Infinity Slayer
 * Big Team Infinity Slayer
 * Rumble Pit
 * Multi-Team
 * Team Action Sack
 * Flood, Team Snipers
 * Regicide
 * SWAT

Team-based scoring playlists are
 * Castle Team DLC
 * Team Objective
 * Capture the Flag
 * Dominion
 * Team Throwdown
 * Team Doubles
 * Grifball