What opening scares you the most?

@Sefegiru
I, also, like to play 3.Bc4 against the Latvian Gambit, but the theory is extensive. Rather than 4...d5?, there is 4...Qg5!, with a dozen moves of theory to follow. Without this in hand, White is doomed.

@iBishop Ah, an interesting line indeed! I have not faced this one so far out of the Latvian, but it reminds me a lot of the Wasp Attack in the Elephant Gambit which is a close relative of the Latvian anyways (and which I played with Black once or twice). 1.e4 e5 2.Nf3 d5 3.Nxe5 dxe4 4.Bc4 Qg5.

Also I have seen some of the motifs in the Schliemann/Jänisch in the Ruy Lopez.

These tactical ideas/motifs are something White needs to know to survive this line, you're right about that.

Given a choice between playing a game with this opening from either the black or the white side, I would much rather be White.

@clousems I'm a d4 player who doesn't play gambits. That's why I'm curious if there are any for white after d4. I play QD and Caro-Kann and am looking to gently branch out...