Ah yes...

Why can't n take the Q?

It is the with this one

Lostcauseone: just to note that the article isn't mine; I just posted a response:)

Lostcauseone - White can't exchange Qs because its Black's move:) Specifically, ...NxQ, and White is d.e.d.

When Black tries this with me (ie 3...Nd4?), moving a piece twice in the opening, I just 0-0. If he exchanges Ns, I get to develop my Q. If he protects his epawn with d6, then I play c3 and gain a tempo that way. In the Blitz game below, we could both have played better but it illustrates the point, I think:)

I'm white......

This opening trap appears to be known as C50: Italian Game: Schilling-Kostic Gambit, and 4.Nxd4, trading the knights, gives a very winnable position for white.

4. c3 with enormous leadin developement and bonus center occupation as well.

The trap is both known as kostics trap or the blackburne [shilling] gambit.  I would say the best continuation is

1. e4 e5

2. Nf3 Nc6

3. Bb5 Nf4?!

4.Nxd4! exd4

5.c3

if 5...Bc5? 6.Bxf7+! Kxf7 7.Qh5+ wins a pawn.

The moral of the blackburne gambit?  look before you leap, whenever your opponent looks like he's made a mistake assume he is setting a trap.  Its not like you are going to be in time trouble on move 4.

It's a good move to know. My play has gone downhill dramatically (lack of practice), so I might try and remember this.

lol noob exchanging the knight wins a tempo on move 3

I hope this will be a big discussion.