According to several reports, 343 industries might be ditching its in-house Slipspace engine for Epic's technologically advanced Unreal Engine 5 for the next version of their signature franchise, Halo.

Switching up an internal engine in favor of the industry-standardized Unreal Engine is not new, as we've seen it several times in the past. Many triple-A titles have undergone an engine change, including the highly-acclaimed The Witcher 4.
A few months ago, Certain Affinity posted a tweet about deepening its relationship with 343 to evolve Halo new ways. The tweet also linked several job listings, including Lead Technical Artist and Senior Technical Animator.
We’ve been part of the @Halo franchise for more than 15 years and we’re honored to say we are deepening our relationship with 343 and have been entrusted with further evolving Halo Infinite in some new and exciting ways. Join us on our journey. https://t.co/fApGobYZS3 pic.twitter.com/XSuS7EtLcq
— Certain Affinity (@CertainAffinity) April 12, 2022
The responsibilities of these roles mentioned "in-depth knowledge of the Unreal game engine for setting up characters, control rigs, simulation, and blueprints."
One other point mentioned the research & development of new technology that may require the use of Maya and Unreal. Per the job postings, the company is clearly looking for developers already well-versed in the Unreal engine.
Industry Insider ACG recently tweeted confirming that many of his sources are talking about Halo's switch to Unreal engine and that it has already been decided internally.
I can only confirm that many sources are saying this and very clear that it's already been decided and Halo is for sure switching to Unreal.
I feel like it's time for other switches behind the scenes including people leaving and their past problems.Unreal is a great choice. https://t.co/8KxMqREWIk
— ACG (@JeremyPenter) October 2, 2022
But why would such a huge company ditch its own engine for an Unreal engine? Because it makes the most sense. The Unreal Engine 5 is currently the leading engine in the market, with the most up-to-date features that help developers create beautiful yet optimized games.
A popular Polish video game studio called Flying Wild Hog (FWH) also ditched its in-house engine, RoadHog Engine, in favor of the updated Unreal engine. FWH will be utilizing Unreal Engine 5 for all its future games.
Many players over on the r/GamingLeaksAndRumours subreddit are still skeptical about the confirmation from ACG, with one of them saying, "This guy was wrong about AC so going to take this with a grain of salt."
In any case, given the optimization issues that Halo Infinite faced, the idea of changing to a more stable engine is not outlandish. Perhaps this change could boost the next Halo game back up to the popularity level it once was.