The fan translations of Sapkowski vs. the professional translation is … well it's pretty iffy.

I read the fan translations initially and I was very concerned. I was wondering "WTH is all this about?" It read like bad gaming fiction to me.

Then last July, I got the professional translation of The Last Wish.

The quality between the two is night and day. Well worth your time and effort - and please don't judge Sapkowski by the work of fan translators.