CD Projekt Red says The Witcher 4 isn't going to happen because the series was always envisioned as a trilogy, nothing more. The critically-acclaimed video game series first debuted with The Witcher in 2007, based on the novel series of the same name by Andrzej Sapkowski, and followed the protagonist Geralt of Rivia, one of the world's last Witchers - people with extraordinary abilities who hunt monsters across the Continent.
The Witcher was enormously successful and spawned a sequel in 2011, The Witcher 2: Assassins of Kings. Whereas the first game was only released on PC (and OS X), the sequel also released on last-generation consoles in addition to Linux, which certainly helped boost its sales. The Witcher 2 also achieved critical acclaim - it was even awarded Game of the Year by some outlets - which is why CD Projekt Red started developing The Witcher 3: Wild Hunt almost immediately after the sequel released. Wild Hunt hit stores shelves in 2015 and concluded Geralt's story and The Witcher video game series. Unfortunately, there won't be another sequel in the future.
CD Projekt Red CEO Adam Kiciński reaffirmed at the Pareto Securities Gaming Seminar last week that they won't make The Witcher 4 because the series was always meant to end with The Witcher 3. Just because The Witcher 4 won't happen, though, that doesn't mean the studio may not decide to produce something within that franchise in the future - a spinoff, maybe.
"We can't create Witcher 4, because that was a trilogy from the beginning. No one said that one day we won't decide to develop something in the Witcher universe. But now we're focusing on Cyberpunk and Gwent."
While CD Projekt Red doesn't plan on developing The Witcher 4, they are still developing the card game Gwent, and they may one day return to the Witcher universe with an actual video game in the future. Based on Kiciński's comments, that game could come in the form of a prequel or spinoff, but not a sequel. Plus, fans of the series can still look forward to Netflix's upcoming Witcher TV series.
As for the studio itself, CD Projekt Red is now turning all their attention towards developing their next blockbuster franchise, Cyberpunk 2077, which was first announced in 2012 but was shelved shortly thereafter so that the development team could focus on producing The Witcher 3. CD Projekt is expected to finally showcase Cyberpunk 2077 at E3 2018 this summer and perhaps even release the game within the next year or two. And if they ever do return to The Witcher series, it would come after Cyberpunk 2077 releases, not before.
Source: Adam Kiciński (via PC Gamer)