Halo 4 is a developed by and published by the . The fourth mainline installment and seventh overall in the , the game was released on November 6, 2012. Halo 4's story follows a enhanced human , , and his construct , as they encounter unknown threats while exploring an ancient civilization's planet. The player assumes the role of Master Chief who battles against a new faction that splintered off from remnants of the , a former military alliance of races, and against mechanical warriors of the empire known as the Prometheans. The game features a selection of equipment, enemies, and game modes not present in previous titles of the series.
Development of Halo 4 began in 2009 and continued until September 2012. Halo 4 is 343 Industries' first original title within the Halo series—previously, development of the main series was undertaken by , the creator of the franchise. In the developmental process, 343 Industries decided to explore the Forerunner fiction within the Halo universe, leading the team to design a new setting, enemies, and main antagonist. Existing characters and assets received visual overhauls, recreated from the ground up, and was used for animation within cutscenes. A goal for Halo 4's story was to incorporate more human elements; to achieve this, the developers chose to delve more deeply into the relationship between the two protagonists, Master Chief and Cortana. Several external studios assisted 343 Industries with developing Halo 4, and over 350 people worked on the game in total.
- More than one million people played Halo 4 on within the first 24 hours of its release
- Halo 4 grossed US$220 million on its launch day and $300 million in its opening week—a record for the franchise.
- The game was marketed with promotional events and videos, including the creation of a live-action film,
- The game was officially announced at (E3) on June 6