Why big studios are giving up their own game engines

On 6 October 2024, just before the grand final of the Halo World Championship, Halo fans watched a seven-minute video with two pieces of news. 343 Industries, Microsoft’s Halo studio, was now called Halo Studios. Every future Halo game would be built in Unreal Engine 5. The engine behind Halo Infinite, Slipspace, was on its way out.

Halo Studios’ art director, Chris Matthews, gave the bluntest reason in an interview with Xbox Wire that day: “Respectfully, some components of Slipspace are almost 25 years old.” Studio head Pierre Hintze described the problem: “On Halo Infinite, we were developing a tech stack that was supposed to set us up for the future, and games at the same time.” Chief operating officer Elizabeth Van Wyck framed the change as a question of “how we help the team focus on making games, versus making the tools and the engines.”

Halo was the latest in a line. In four years, four large studios had said the same thing in different words.

The same sentence, four times

Konami went first. In July 2020 it announced that Pro Evolution Soccer would leave the Fox Engine, the technology Kojima Productions built for Metal Gear Solid V, for Unreal. The series producer, Seitaro Kimura, later told IGN that “Unreal Engine’s development speed is one of the fastest among game engines,” and told TechRadar how the decision formed: “at UNREAL FEST, I was able to listen to development case studies of titles that had adopted Unreal Engine.” According to IGN, the football itself still runs on Konami’s own custom systems on top of Unreal, so this was a partial move.

In March 2022 CD Projekt Red announced it would build its next Witcher on Unreal Engine 5 and retire REDengine, told in full in why CD Projekt Red left REDengine. Its CTO, Paweł Zawodny, said the studio had “spent a lot of resources and energy to evolve and adapt REDengine with every subsequent game release.”

Two weeks later, on the day Epic released Unreal Engine 5, Crystal Dynamics said its next Tomb Raider would use it too. At Unreal Fest that year, executive producer Ben Irving put the choice in one line: “do we want to be a game team that builds engines or a team that builds games.” The studio had worked on its own Foundation Engine for about 20 years, through two rewrites, according to Tomb Raider Chronicles’ report of the talk. Irving also admitted the idea was not new: “In Crystal’s history we actually had talked about moving to Unreal Engine several times and decided to not do it.”

Then came Halo. Each time the reason came back to the same point: maintaining an engine takes developers away from the game.

EA went the other way, sort of

Electronic Arts is the counterweight. Around 2015 it set out to put its games on Frostbite, the engine DICE built for Battlefield. That included role-playing games like Dragon Age and Mass Effect, on an engine first made for shooters. Aaryn Flynn, BioWare’s former general manager, later called Frostbite “very delicate and hard to manage”. How much EA pushed is disputed: Flynn has also said moving to Frostbite was BioWare’s own decision.

In December 2023 EA changed its policy and told its studios they could use any engine they wanted. That did not mean leaving Frostbite. EA said the engine had helped launch six games that year, from Dead Space to EA Sports FC 24, and Frostbite’s general manager, Tim Cowan, was frank about why moving is no shortcut: “Changing engines is hard, regardless of the engine.” His case for keeping it was control: “We can bend this engine to our will and make it do the things we need it to do.”

The quiet one

Square Enix’s Luminous Engine ended without a statement. On 28 February 2023 Square Enix announced that Luminous Productions, the studio founded to make games on the engine, would merge into Square Enix on 1 May. Game Developer noted the news came just over a month after Luminous released Forspoken. Square Enix never said what would happen to the engine, and no later game on it has turned up in our research.

What Unreal does not fix

Moving to Unreal brings its own problems. When Digital Foundry looked at Halo Studios’ first Unreal footage, it pointed out that on PC, “shader compilation and traversal stuttering never seems too far away” in Unreal Engine 5 games, even big-budget ones. For open-world games in the Halo mould it singled out traversal stutter, which it said “must not be a part of any future game in the series.” The first of those hitches has its own entry in our glossary: shader compilation stutter.

So the pattern is clear without being universal. Studios with an aging engine and a big new game ahead have been choosing Unreal, and saying it is about making games instead of making tools. EA, with many teams already on its engine, kept Frostbite and loosened the rules. And Crystal Dynamics shows how long these decisions take: by Irving’s account, the studio talked itself out of Unreal several times before it finally said yes.

Sources

Checked November 3, 2026.

1. Halo Studios: New Name, New Engine, New Games, New Philosophy — Xbox Wire
2. Future Halo Games Moving to Unreal Engine 5 as 343 Industries Rebrands — IGN
3. Halo is moving to Unreal Engine 5 - and the first footage looks impressive — Digital Foundry
4. Tomb Raider dev discusses move to Unreal Engine — Tomb Raider Chronicles
5. How the (pro) evolution of Konami's eFootball came to be — TechRadar
6. How Unreal Engine Helped Turn PES Into eFootball — IGN
7. Announcing a new look and vision for EA's Frostbite engine — Electronic Arts
8. Why does EA's internal engine Frostbite have a public-facing brand? — GamesIndustry.biz
9. EA rebrands Frostbite with a cuddly new hand as it says its studios are now free to develop on any engine they choose — PC Gamer
10. Reorganization within the SQUARE ENIX GROUP — Square Enix Holdings

Image credits

• Crowds of developers at the Epic Games and Unreal Engine booth on the expo floor of the Game Developers Conference, March 2017 — Official GDC. CC BY 2.0. Cropped and converted to WebP