Blackmar Diemer Gambit and the Scandinavian Defense

Is the Blackmar Diemer Gambit similar to the Scandinavian Gambit in terms of theory and imbalances?

I am a fan of the Scandinavian Defense as a surprise weapon in tournament play, but right now I feel like I have no similar openings to use for white .... Well that was until I encountered the Blackmar Diemer Gambit, in the Scandinavian Gambit I normally find myself up in development and a pawn down but after taking (1. e4 d5 2. d4 dxe5) I shortly found myself in a role-reversal. At first I was annoyed that I didn't just go transpose into the Caro Kann once I saw 2. d4, but now I think it my have been luck that I encountered this intresting opening for white. As white I usually play 1.d4 or 1.Nf3, so I would not be on uncommon ground.

Note: I want to know if the BDG is similar to the Scandinavian Gambit, not that either is unsound. I use the Scandinavian Defense as a surprise weapon, so it is not the only response I have to e4 (I use it in addition to the Caro Kann and the French Defense, who all can transpose into on another).

In the BDG, White tries to develop and regain his pawn(Nc3 is the most common way to do this) while Black tries to hold on to it or let White waste a tempo regaining it while attempting to out-develop White.

In the Scandinavian, Black usually plays Nf6 and after Nc3 c6 would be a solid move, because if dxc6 then Nxc6 and Black has an edge. But if White plays d4 in the Scandinavian and Black then plays Nc6 it can veer off in a wildly different direction from BDG.

Conclusion:In both openings, both sides try to out-develop each other, but the Scandinavian can quickly turn to something else altogether, while the BDG stays roughly the same.

 The Scandinavian Gambit is what I had in mind, I completely agree the mainline is not similar (as White gets more development kicking around your Queen).

Thank you for your complete answer. I myself enjoy the Scandinavian Gambit which is what I meant to compare to the Blackmar Diemer Gambit mainline with the recapture on with the Knight on c3. Would you suggest the Blackmar Diemer Gambit to someone who often enjoys the Tactical/Dynamic qualities of the Scandinavian Gambit and Icelandic Gambit? Also is there any lines of books you recommend me study on this opening?

I always play the Scandinavian Gambit myself if I decide to play the Scandinavian Defence(because if Qxd5 then Nc3 and white gains a tempo. The best reply is Qa5 but if white can lock the centre then your Queen might be stranded on the Queenside). If you didn't know, after dxc6 Nxc6 is the best reply, acheiving a neat lead in development for a pawn.

The Blackmar Diemer, while dynamic and tactical, can also be rather sharp, and proper play by black will ensure that he has a solid edge which he can exploit against you in the future. And remember that you have you get back your pawn as quickly as possible.

I must also warn you that after a certain line of the S-Gambit( I think it was 1.e4 d5 2.exd5 Nf6 3.c4 c6 4.d4) it transposes to some variation of the Caro-Kann. This part is a bit murky as I heard it second-hand from a chess buddy of mind last year.

I think the variation you are talking about is the Panov–Botvinnik Attack. Order goes 1.e4 d5 2.exd5 Nf6 3.c4 c6 4.d4 cxd5. This regains Black's pawn, but lets White obtain a position that seems similar to the Queen's Gambit. Since I play the Caro Kann and the Nimzo Indian, I like that variation because it can transpose into either mattering on White's next move.

I enjoy dynamic and tactical openings, so I think I will give it a try and fold it into my chess repertoire. I probably will try and get a book about the Blackmar Diemer Gambit (the one by Tim Sawyer) because it is most definently sharp from the games I have been watching. When I've finished the book and tried it out online, I will use it in tournament play (this way the sharp lines won't be destroying me).

In the Scandinavian Gambit, I like to play the Ross rather than immediately recapturing if White accepts the pawn on c6, that is:

1. e4d52. exd5Nf63. c4c64. dxc6e5

kind of like a Danish Gambit reversed where two pawns are offered.  There is an analysis of this variation on this website and also a brief discussion here at chess.com here.