In spite of his youthful appearance and reckless behavior, the bard Dandelion is supposed to be in his late forties by the time of the game's events. This is actually true to the books, where, a few years before, Dijkstra told Dandelion: "I know you're almost forty, look almost thirty, think you're just over twenty and act as though you're barely ten."
Doug Cockle (who voices Geralt in the English version of the game) said in an interview that he had not played any Witcher game previously in the series, but says that he bought a console this time to finally play Witcher 3 when it releases.
When Geralt in conversation makes the hand motions for the sign "Axii", he is actually spelling it using letters from American Sign Language.
Has real in-game beard growth.
If you fall off a cliff in the game, there's a very rare chance of hearing the Wilhelm Scream.