"According to the fair play of the world,
Let me have audience..."
See in text (Act V - Act V, Scene 2)
In this second instance of Philip's use of the term "fair play," he uses the term to seek an audience with the Pope's legate as courtesy and chivalry demand. However, he still expresses some sarcasm, because the point of seeking this audience is to reject the peace deal with the Pope and the surrender to France. He uses "fair play" as a customary courtesy, a show of civility, to indicate that he desires a peaceful audience—even with those he may hate enough to harm. This expression represents a mark of civility for us (like playing by the rules of the game), but Philip considers it merely an ambivalent quality, a not always necessary evil.