Initially, Cavill went with something that sounded like his natural accent after listening to the audiobooks narrated by voice actor Peter Kenny. It fit with the books, particularly the first one, where Geralt is pretty chatty and the language is a bit flowery. In the show, however, the first two books are being condensed into eight episodes, so Cavill had to find a way to express who Geralt was without a stream of dialogue.
"When I heard Doug Cockle’s incredible performance in Witcher 3—which I’ve heard time after time because I’ve played the games a lot—I realised that I could utilise something like that, and create [Geralt's] stony exterior," Cavill said.
To my ears, an American accent usually sounds too modern, for some reason, to fit in a medieval fantasy setting, but I now can't think of Geralt without also hearing Doug Cockle. Cavill has tried to keep his natural accent, but he's picked up Cockle's gravelly tone, though it's deeper, apparently, where Cockle's was more of a whisper. He reckons it shows the "boiled-down essence of who Geralt was".
I'm looking forward to the show, but it's still going to have a hard time convincing me that CDPR and Cockle's version of Geralt isn't the best, though I can't deny Cavill looks pretty good in a tub.
The Witcher airs on Netflix on December 20.