Rank (Halo 4)

The ranking system in Halo 4 is based on XP earned through Multiplayer, Forge, and Campaign 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.

Overview
Players begin their careers in the base SPARTAN-IV ranks. There are 50 ranks to work your way through, from SR-1 to SR-50, unlocking gameplay and visual customization items as you rank up.