CD Projekt explains why The Witcher 4 is using Unreal Engine 5

It was a very big deal when CD Projekt finally confirmed in March that The Witcher 4 (not the official title, but what we're rolling with for now) is in development. Also unexpected was the news that it is not developing the game using a new iteration of its REDengine, but will instead use Unreal Engine 5. During today's State of Unreal event, members of the studio touched on why that change was made.

"There was one demo that happened last year, that was the medieval environment demo, where at one point there's a notice board that looks strangely familiar to things we've done in the past – that has even a sign that says 'monster slayer wanted'," Slama says in the video. "And I'm like, 'Hmm, are they trying to tell us, come over to Unreal Engine, look how great your games can look on there? Was that whole demo made with that nefarious purpose?' I don't know, but it definitely caught my eye."

That "monster slayer wanted" image is actually from a multi-part tutorial, which you can see below, on creating medieval environments in Unreal Engine 4. Engine specifics notwithstanding, it does seem like a clear call-out of The Witcher, a faux-medieval monster hunter who often picks up work from local notice boards.

Of course, catching someone's eye is a long way from convincing studio leadership to switch to a whole new engine. REDengine has impressive capabilities but building, maintaining, and upgrading it from game to game is a major drain on development resources. Shifting to Unreal Engine 5 enables CD Projekt to leave much of the engine-level development to Epic, allowing it to focus primarily on making an actual game.

"Unreal Engine is like a toolbox which has a lot of features, a lot of solutions, already there that allows teams to just try new stuff," VFX and lighting art director Jakub Knapik said. "The fact that Unreal is used by a lot of teams already in the world, a lot of perspectives are projected into the design of the tools, and that helps the tool to be way more agile."

Here's that tutorial segment:

Another big part of the decision to switch to Unreal Engine for the new Witcher game is its open world-specific capabilities, which Slama said will make it easier for developers to deal with the "exponentially higher" number of problems they'll run into while making open worlds compared to linear games.

"Players can go in whatever direction they want, they can handle content in any order that they want, theoretically," Slama said. "To really encapsulate that, you need a really stable environment where you can be able to make changes with a high level of confidence that it's not going to break in 1,600 other places down the line."

Speaking strictly for myself, I don't care what engine CD Projekt, or any other studio, decides to roll with: I'm here to be impressed by games, not technology. But if switching to someone else's engine facilitates the process of making good games—and CD Projekt clearly seems to think it will—then I'm all for it. 

It's not the only studio to come to that conclusion: Crystal Dynamics announced today that it's working on a new Tomb Raider game using Unreal Engine 5, too. The previous Tomb Raider trilogy uses Crystal Dynamics' own Foundation engine.