idbeholdME: Just using Unreal Engine doesn't automatically mean the 1 year exclusivity deal. As for whether they decide to go that route with the next Witcher, I highly doubt it.
MMM96: They have signed a fifteen-year agreement to use the graphics engine in their next games, so Epic Games must be making some profit from it.
Yes, it is called licensing fees and royalties.
"Unreal Engine is free to use for students, educators, hobbyists, and most non-games companies making less than $1 million USD in annual gross revenue.
- For game developers and other users distributing applications that incorporate Unreal Engine code at runtime (such as a game) and are licensed to third-party end users, a 5% royalty is due (discounts may apply) when the lifetime gross revenue from that product exceeds $1 million USD. No royalties are due on the first $1 million in lifetime gross product revenue.
- For other companies, if you earn over $1 million USD in annual gross revenue, you will need to buy Unreal Subscription seats. Unreal Subscription costs $1,850 per user per year, and includes Unreal Engine, Twinmotion, and RealityCapture.
- There are also options for custom terms that can include Epic Direct Support, private training, negotiated terms for lower royalties, and more. Contact us to discuss your needs."
https://www.unrealengine.com/en-US/faq