Cyberpunk 2077 Engine: REDengine 4 Explained
1 min read
The last game CD Projekt ever built on its own engine — everything after this, including the sequel, moves to Unreal.
The Cyberpunk 2077 engine is REDengine 4, the fourth and final version of CD Projekt's proprietary engine, built up across the studio's own games rather than licensed from anyone else.
The lineage
REDengine started with The Witcher 2 and was refined through The Witcher 3 before this iteration was built specifically to handle Night City's dense, vertical open world — a very different technical problem to a rural fantasy landscape.
Why it stops here
Cyberpunk 2077 is the last title CD Projekt built on REDengine. The studio has since moved to Unreal Engine 5 for its future projects, including the Cyberpunk sequel currently in development. Maintaining an in-house engine at the scale modern open-world games demand was judged not worth the cost against adopting established, actively updated tech.
What that means for this game
Cyberpunk 2077 will never be rebuilt on Unreal — it stays on REDengine 4 for the rest of its support lifecycle, patches included. Anything genuinely new from the studio, engine-wise, belongs to whatever comes next rather than to this game.