With 4.Nc3, the Quaade Gambit, White indirectly defends against Black's threat of 4...g4 to kick away White's knight. Unlike the direct responses of 4.h4 and 4.Bc4, or the other indirect response of 4.d4, the move 4.Nc3 doesn't even seem to begin to defend against the threat of 4...g4, but it does.

After 4...g4 5.Ne5 Qh4+ 6.g3 fxg3, the move 7.Qxg4 saves the day for White; best for Black is to trade queens and go into a queenless middlegame that is still incredibly tricky for Black. However, most people blunder with 7...g2+ 8.Qxh4 gxh1=Q, a tempting sequence that wins material but puts Black's king in severe danger. White is winning after 9.Qh5, threatening a Scholar's Mate. Black must find several only moves to defend an immediate mate, and even after a good defense, White's knight on c3 jumps to d5 with devastating effect, crushing Black.

A better option after 4...g4 5.Ne5 is for Black to strike with 5...d5, immediately giving the pawn back. White still gets a very fun and violent attacking game.

Instead of 5.Ne5, the move 5.Bc4 transposes to the McDonnell Gambit, and the move 5.d4 transposes to the Sorensen Gambit--both with the intent to give up the knight on f3 and go for initiative.