User blog comment:The Dragon Demands/Slapping Joffrey compilation (set to "Sweet Dreams are Made of These")/@comment-5014364-20120607163342

Tywin "saving" Gendry isn't fundamentally different from the books. He isn't the kind of man who tortures peoples (unless he wants to teach Tyrion a "sharp lesson"...)

Tywin usually offers peace to enemies that submit, so make sure they keep serving him.

I thought the TV scene played this very accurately: he's an intelligent pragmatist, even if he is ruthless and self-interested. He's vicious, but not an idiot, in direct contrast to how Joffrey is a vicious-idiot --> that is, he stops the torturing by phrasing it in pragmatic terms, "is the war effort doing so well that we can afford to throw away young bodies and skilled laborers?", and the dirty look he shoots the Lannister guards when Gendry reveals that he is a blacksmith, which is something they actually really need.