Are there any gambits where you sack a piece?

The one I played.

well, I think i don't need to help you...you get the help you need :)

I'm out..good luck

Yes. It is not common, but if someone plays the Damiano Defense you can play the Damiano Gambit. It almost never fails. Even the great Bobby Fischer approved of it.

There is also this one for Black against the Glek 4 Knights:

I analyzed Traxler into about move 40 ( 80 ply ) and white can win after 5.Nxf7.

*CAN'T WIN

*CAN'T WIN

because this i ask,is for play in blitz or online chess? i have no answer

but this strong brazilian player i know,play in online games...i can put she in touch whith him....if she wants,of course...but here there a lot of experts os i will be quiet

Nakhmanson gambit Luccini Gambit

In King's gambit, there is a variation where you sac the knight on f3.

Caro-Cann Caveman variation has a rook sacrifice.

After Qb3, white sacrifices the pawn with Bd3. After Bxd3, white recaptures with the queen and black plays Qxb2 gaining a pawn. White sacrifices the rook by playing Nf3. Black accepts the sacrifice with Qxa1?? White play Qb3 preparing to win the queen. Black plays e6 and white castles preparing to win the queen for the rook, and black plays b5 to prevent Nc6, and white plays Nd2 winning the queen.

Another one would be the Muzio gambit.

White sacrifices the f3 knight for a strong attack on the f file. After Qf6, white plays e6 sacrificing another pawn. After black captures, white plays Bxf7, sacrificing the bishop to expose the king. After Kxf7, d4, sacrificing another pawn and opening the d file for counterplay. If Qxd4, white plays Be3. Qxe3?? loses to Qxe3, because the pawn is pinned. Qxb2?? also loses because it allows white to quickly attack with Qxf4+. White is sacrificing pieces and pawns to get a huge amount of counterplay and attack black's king.

The Cochrane gambit is a more positional gambit.

I don't know too much about this gambit as I haven't played it before, but this gambit is a more positional gambit. In most lines white is aiming to gain a positional advantage in the center.

Next, we have a queen sacrifice in the Grand Prix Attack.

Very few play this gambit and even less allow it. If you're wondering why black played Kc3=6 and not Ke8 is because if Ke8, white would play Bf7+, then Kd7, and then Ke6+ repeating the position again. White is sacrificing a queen for two minor pieces, and is aiming to restrict black's play. I haven't done much study on this, so I may be wrong on the details.

Now one of the most popular, the Fried Liver Attack.

After Kxf7, Qf3+ is played and putting a lot of stress on black's position. It is important to play Ke6 and not Kg8 as Kg8 would lead to checkmate for white. This attack, does have a drawback. Black, if they have memorized the perfect play for their side, can end up winning.

As you can see, black is still not losing and has chances of winning.

And now, the Traxxler counterattack.

Black sacrifices a fork, but after Nxf7, black plays the crazy line Bxf2+! If Kxf7 white can get into all sorts of trouble after Nxe4+, but with perfect play, white can escape with a minor advantage. I don't know much about this counterattack, but I do know that this is a very reliable gambit.

Next, we have the Ponziani-Steintitz gambit.

If Nxe4, Black forks the knight and bishop with d5, and the game continues normally. However, if Nxf7, Qh5 is the move you should play. I don't know much about this gambit, feel free to study it.

The final one I'll cover is the Nakhmason gambit.

After sacrificing two pawns, white sacrifices a knight! After dxc3, white plays Bxf7+, and if Kxf7, Qd5 check wins the knight back. I don't know much about this gambit either, so feel free to check it out.

A few other gambits would be the Halloween gambit, Reverse Halloween gambit, and the Damiano gambit.

These are the only two gambits I know of in which a piece is sacrificed (as part of the defining moves of the gambit) and yet the position is still fully objectively sound.

All the other piece gambits I can think of range from dubious to losing, not that it matters for practical play.

Edit: there's also the fried liver attack, which I forgot about.

Smith Morra, there are a lot of sacrifices there but you need a guide for that probably a book.

Scheveningen, Delayed Keres Attack, Perenyi Gambit

Polgar played an amazing game.

Classical Najdorf, 10. Bd3 side line

Yes, that game against Anand was very beautiful. I believe in that game she played 13. Bd2.