Smith–Morra Gambit

In chess, the Smith–Morra Gambit (or simply Morra Gambit) is an opening gambit against the Sicilian Defence distinguished by the moves:
 * 1. e4 c5
 * 2. d4 cxd4
 * 3. c3

White sacrifices a pawn to quickly and create attacking chances. In exchange for the gambit pawn, White has a piece developed after 4.Nxc3 and a pawn in the, while Black has an extra pawn and a central pawn majority. The plan for White is straightforward and consists of placing his bishop on c4 to attack the f7-square, and controlling both the c- and d- with rooks, taking advantage of the fact that Black can hardly find a suitable place to post his queen.

The Smith–Morra is uncommon in grandmaster games, but is popular at club level. It does not have a definitive refutation.

History
The Smith–Morra is named after Pierre Morra (1900–1969) from France, and Ken Smith (1930–1999) of the Dallas Chess Club. In Europe the name Morra Gambit is preferred; other names for it, including Tartakower Gambit and Matulovic Gambit, have disappeared.

Around 1950, Morra published a booklet and several articles about the Smith–Morra. Smith wrote a total of nine books and forty-nine articles about the gambit. At the San Antonio 1972 chess tournament, Smith played it against Donald Byrne, Larry Evans, and Henrique Mecking, but lost all three games.

Many players consider the opening amateurish. International Master Marc Esserman, author of the 2012 book Mayhem in the Morra!, is one of its leading advocates. In the Chessable Masters tournament in April 2023, Hikaru Nakamura played it in two rapid games against Fabiano Caruana, winning one and losing the other.

Continuations overview
Black has a wide choice of reasonable defences after 1.e4 c5 2.d4 cxd4 3.c3. White sometimes plays 2.Nf3 and 3.c3, which depending on Black's response may rule out certain lines. 3.Qxd4 Nc6 4.Qe3 is the Sicilian Center Game, similar to the Center Game, 1.e4 e5 2.d4 exd4 3.Qxd4 Nc6 4.Qe3.

Themes for White
In return for the sacrificed pawn, White acquires a number of benefits that can be used to create active plans: The mix of short- and long-term ideas means that the character of positions arising from this gambit can be described as a mix of the Stafford Gambit and the Benko Gambit: to survive against a well-prepared White player, Black must first navigate the minefield of traps in the opening, then contend with White's long-term pressure and initiative. If Black manages to do this while holding on to the extra pawn, he/she will have good chances to win the ensuing endgame. This is not easy, however, and many Sicilian players opt to decline the gambit altogether.
 * Active development and quick castling. White's development scheme usually (but not always, as the Siberian trap demonstrates) consists of Nf3, Bc4, 0-0, Qe2, Rfd1, and Rac1 in some order.
 * Additionally, the Bc1 will often develop to g5 when Black plays ...Nge7 to make it difficult for Black to continue developing without weakening the kingside slightly by ...h6 or ...f6.
 * Prevention or delay of Black's castling. This can open the door for powerful sacrificial ideas which, when correctly timed, can devastate the Black king:
 * When Black's king is uncastled, the sacrifice Nd5! is especially powerful with a Black pawn on e6, as the recapture ...exd5 would allow White to open the e-file for the White rook or queen. In two notable games, Esserman defeated GM Loek van Wely and GM Dommaraju Gukesh using this sacrifice.
 * Another idea is Nxb5! with Black pawns on a6 and b5. Although not as common as Nd5!, it is possible in some lines like the Chicago Defence when Black is slow to castle. Occasionally, it is even possible when Black is castled if White's tactics on the queenside justify it.
 * The sacrifice Bxe6! is typical for Sicilian positions and can sometimes occur here as well.
 * Pressure down the c- and d- files, usually achieved with rooks on c1 and d1.
 * A long-lasting initiative that can be used to create a kingside attack.

Scheveningen Formation

 * Classical Main line: 4...Nc6 5.Nf3 d6 6.Bc4 e6 7.0-0 Nf6 8.Qe2 Be7 9.Rd1 e5 10.h3 or 10.Be3
 * Scheveningen setup: 4...Nc6 5.Nf3 d6 6.Bc4 e6 7.0-0 Nf6 (or Be7) 8.Qe2 a6 9.Rd1 Qc7 (probably inferior Qa5) 10.Bf4 (10.Bg5) Be7


 * Siberian Variation: 4...Nc6 5.Nf3 e6 6.Bc4 Nf6 and 7...Qc7, with the idea being after 7.0-0 Qc7 8.Qe2 Ng4!, 9.h3?? loses to the famous "Siberian Trap" 9...Nd4!, winning the queen. If instead White plays 9.Rd1, preventing 9...Nd4, Black can continue with 9...Bc5 with a clearly better game.

Paulsen Formation

 * 4...Nc6 (or 4...e6) 5.Nf3 e6 6.Bc4 a6 (Nge7) 7.0-0 Nge7 (d6 8.Qe2 Nge7 9.Bg5 h6) 8.Bg5 f6 9.Be3

Kan Formation

 * 4...e6 5. Nf3 a6

Larsen Defense

 * 4...Nc6 5. Nf3 e6 6. Bc4 Qc7 7. Qe2 a6 8. O-O Bd6

Morphy Defense

 * 4...Nc6 5. Nf3 e6 6. Bc4 Bc5

Morphy Defense Deferred

 * 4...Nc6 5.Nf3 e6 6.Bc4 a6 7.O-O b5 8.Bb3 Bc5

Pin Defense

 * 4...Nc6 5.Nf3 e6 6.Bc4 Bb4

Sozin Formation

 * 4...Nc6 5.Bc4 e6 6.Nf3 d6 7.O-O a6 8.Qe2 b5

Taimanov Formation

 * 4...e6 5.Bc4 a6 6.Nf3 Ne7

Classical Formation

 * 4...Nc6 5.Nf3 d6 6.Bc4 a6 eventually 7...Bg4

Fianchetto Formation

 * Fianchetto: 4...g6 (4...Nc6 5.Nf3 g6 allows 6.h4!?) 5.Nf3 Bg7 6.Bc4 Nc6

Chicago Defense

 * 4...d6 5. Nf3 e6 6. Bc4 Nf6 7. O-O a6
 * 4...e6 5.Bc4 a6 6.Nf3 b5 7.Bb3 d6 8.0-0 and Black plays ...Ra7 at some stage
 * Early queenside fianchetto: 4...e6 5.Bc4 a6 6.Nf3 b5 7.Bb3 Bb7
 * 4...Nc6 5. Bc4 e6 6. Nf3 d6 7. O-O a6 8. Qe2 b5 9. Bb3 Ra7

Finegold Defense

 * 4...d6 5. Nf3 e6 6. Bc4 Nf6 7. 0-0 Be7 8. Qe2 a6

4.Bc4 or 4.Nf3
This line is similar to the Danish Gambit: 4...cxb2 5.Bxb2

Morra Gambit Declined

 * Advance (or Push) Variation: 3...d3
 * Dubois Variation 4.c4
 * Alapin Variation: 3...Nf6 4.e5 Nd5
 * Scandinavian Formation: 3...d5 4.exd5 Qxd5 (Nf6) 5.cxd4
 * Center Formation: 3...e5
 * Wing Formation: 3...Qa5