Rank (Halo 4)

The Spartan Rank system in Halo 4 is based on XP earned through Multiplayer and Forge matches. Players gain XP by playing War Games (earning more for winning and high personal score), playing Spartan Ops (earning more for higher difficulties), completing each level of a Commendation, completing Challenges, and using Forge. After reaching level 50, the player is allowed to earn specializations

Overview
Players begin their careers in the base SPARTAN-IV ranks. There are 130 ranks in total, from SR-1 to SR-130, unlocking gameplay and visual customization items as the player ranks up.