HAN: Let him have it. It's not wise to upset a Wookiee.
THREEPIO: But sir, nobody worries about upsetting a droid.
HAN: That's 'cause droids don't pull people's arms out of the sockets when they lose. Wookiees are known to do that.
THREEPIO: I see your point, sir. I suggest a new strategy, Artoo: let the Wookiee win.