Halo: Reach designer Niles Sankey has revealed that the campaign of Bungie's final Halo title drew heavily on the first two Call of Duty: Modern Warfare games, despite the two franchises being fierce rivals in the mid-2000s. Responding to a social media post about Modern Warfare's notorious nuke sequence, Sankey said Bungie admired Infinity Ward's storytelling even while believing Halo excelled elsewhere, such as enemy AI and vehicle combat, prompting the studio to borrow techniques where its rival was stronger. The admission is notable given the intense competition between the series at the time, which even saw Infinity Ward secretly prototype a sci-fi shooter nicknamed "Halo Killer" during Call of Duty 4's development.

Sankey specifically credited Infinity Ward's influence for Reach's Noble Team squad interactions and its "Tsavo Highway"-style "Objective Survive" sequence, which he said was spiritually inspired by Modern Warfare's nuke scene, with Bungie aiming to "push it one step further." Released in 2010, Halo: Reach was Bungie's last entry in the series before handing development to 343 Industries, and is often regarded as one of its finest for its darker, more grounded and tragic storytelling. The article notes that Halo co-creator Jason Jones has recently called for the franchise to return to that tone, though whether this happens remains uncertain.