What's the worst move I played in this game?

As an e4-type player, I can honestly say I've never played against any d4 openings (at least so far as I can remember). Thus, my opponent rightfully swept me off the board, even though I never expected to win my first game through an opening I was utterly unfamiliar with. If you have the patience, please point out the worst thing I did and why I should never do it again in my lifetime.

It amazes me how a d4-opening game can be completely different from an e4 one. In summary, what's the worst thing I can be sure never to attempt again in any setting? Thanks in advance.

I'd say Ng4 was the worst move. After that, your game just crashed and burned.You left a few pawns hanging like on f7/g7 but it seems like you went down after Ng4 so I'm guna call that the worst move.

g5 I am skeptical about. I can kinda see why you would play that move strategically but even if you had played the more correct Ne4, f7 was hanging too.

before g5, you were fine.

Btw, just fyi, tahts not how d4 openings go normally at all. As you get to higher levels, you will see d4 more often. The real d4 line is in the domain of the Queens Gambit (1.d4 d5 2.c4) and Indian Defences (1.d4 Nf6 2.c4), both very, very theoretical and played by many top players today.

What your opponent played is some insanely passive moves early on that basically gave you an advantage before you dropped a pawn with g5 and a piece with Ng4. And also, I would advise against playing Nc6 in any Double QP opening. You generally want to leave the option of c5 or c6 and develop the knight to d7.

I think you're out-thinking yourself here - nobody 'rightfully' wipes anyone off the board at your level. Do you know the basic opening principles 1. Central control, 2. Pieces out, 3. King safety? That, and a little common sense, is all you need for any type of opening in low-level games.

Some annotated comments:

I appreciate the comments, LR and b1. It's good to receive some pointers, especially in an opening where I was quite uncomfortable playing.

@b1: I meant the Fishing Pole trap, arising after a Ruy Lopes. Other than a major difference of the lack of a h-pawn to capture white's pawn after the knight is taken, the other elements was there (that's what I was thinking when I meant "harrassing the king at h2"). But it would fail anyway, so it's no bother. If this game wasn't live, I probably wouldn't have made so many mistakes - would've still lost, I reckon, but not by such a margin.

Thanks, fellas.

Musicman still had 2 pieces on the back rank this could have helped (= ) things out for awhile, ( still down a piece, might as well resign, the hope is he will make a mistake too)  you had more active pieces so that should be an advantage you did not put to your best use. 13... Ne4 is a good outpost, and then you least get a pawn back with open lines if white takes the f pawn. It seems that the 1st ( ?? )caused most of the problems but may not the be the whole problem, its the need to apply principles that caused more pain. You can play a piece down for awhile assume your opponent will not lose any material, its lost already, but when you trade while down material in this case you only get more of the same results. Always going to be tough to play down a piece.

The reason you lost is because you hung the knight without realizing that a check came with it once the queen took. Furthermore you had to attack even at the risk of losing a pawn because a lot of your opponents opening moves were passive like h3 and a3. They were not prophylactic because the correct moves in almost all d4 openings for white is to strike the center with c4 not to waste time moving pawns that do nothing.

 d5 was the worst move. I hate that one. Look up the Nimzo Indian Defense and the Queens Indian Defense and never play d5 again.

I agree with d5 being the worse but I prefer Kings Indian Defenses and the Grunfeld.

The worst move here is you "started the game at all"

I disagree about the annotations about the game.

That was funny! You should annotate more games. I laughed for the first time today when I read that. Now I'm in a good mood.