user31663: Related
The Smith-Morra gambit, or the Morra gambit, is where white sacrifices one pawn to get early development while black has not really done anything. This gambit is also used against the Sicilian defense
[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR"]
[Title "Morra gambit"]
1. e4 c5 2. d4 cxd4 3. c3 dxc3 4. Nxc3

What are the pros and cons of using this opening and does the extra pawn black has compensate for the lack of development, also what are white`s plans using this opening?

user1711: I've played and studied the Morra Gambit for several decades, so I hopefully understand it fairly well. I also have an enormous game database and related notebook with themes, ideas, variations, engine analysis, theoretical novelties, etc.
The first point to make is that the pros and cons vary a lot depending on your own strength and the strength of your opponents. Playing the Morra at Elo/Glicko 1500 level is very different to playing it at 2500 level. The following notes are based on the pros and cons for a player rated around 2000 playing against opponents rated 1800-2300. Other people can answer for lower or higher rating ranges.
Pros:

Works well if you want to take your opponent away from his/her main Sicilian repertoire.
Works well if you play the Morra regularly, but your opponent only sees it once a year or less.
Good if you like tactical and uncompromising play because White's better development often leads to a dangerous initiative.
The ability to calculate deeply and accurately is rewarded more often than in most other openings.
Many of the positions that arise from the accepted gambit are difficult for Black to play, especially if s/he isn't familiar with them.

Cons:

You're a pawn down! So the pressure is initially on White to show justification for that pawn.
You also have to study the Alapin closely because many Black players decline the gambit and forcibly transpose into that variation.
The ability to calculate deeply and accurately is more important than in most other openings.
Requires you to spend lots of time memorising complex variations because Black has a lot of flexibility in responding to the gambit and there is a large volume of theory to study.
If Black has studied at least one defensive line in great detail, you might be the one who runs into nasty variations.

Let's start our understanding of the main Morra systems with a summary of the Classical Main Line.
[Event "Morra Gambit Accepted - Classical Main Line"]
[ECO "B21"]
[FEN "RNBQKBNR/PPPPPPPP/8/8/8/8/pppppppp/rnbqkbnr b KQkq - 1"]

1.e4 c5 2.d4 cxd4 3.c3 dxc3 4.Nxc3 Nc6 5.Nf3 e6 6.Bc4 d6 7.O-O Nf6 8.Qe2 Be7 9.Rd1 e5  

This is a solid system characterised by Black's control of d4, prevention of the e4-e5 break (one of White's main tactical motifs in the Morra), and Black's king safety after castling short. White's main compensation is positional - control of d5, a backward pawn weakness on d6, and Black's somewhat passive position. White should focus mainly on active play in the centre and on the Q-side.
Moving on to a summary of the Qc7 System.
[Event "Morra Gambit Accepted - Qc7 System"]
[ECO "B21"]
[FEN "RNBQKBNR/PPPPPPPP/8/8/8/8/pppppppp/rnbqkbnr b KQkq - 1"]

1.e4 c5 2.d4 cxd4 3.c3 dxc3 4.Nxc3 Nc6 5.Nf3 e6 6.Bc4 d6 7.O-O a6 8.Qe2 Be7 9.Rd1 Qc7 10.Bf4 Nf6   

Black moves the queen off the dangerous d-file and strengthens control of the important e5 square. White looks carefully at the e4-e5 break and sacrificing on d5 or b5, while Black typically positions the queen on b8 and tries for the b7-b5 break. This is a dangerous system for Black and has led to many spectacular White victories. But Black should be okay if s/he plays very carefully.
Moving on to a summary of the Taylor System.
[Event "Morra Gambit Accepted - Taylor System"]
[ECO "B21"]
[FEN "RNBQKBNR/PPPPPPPP/8/8/8/8/pppppppp/rnbqkbnr b KQkq - 1"]

1.e4 c5 2.d4 cxd4 3.c3 dxc3 4.Nxc3 Nc6 5.Nf3 d6 6.Bc4 a6    

This system has been quite popular in the past few years. Black protects the b5 square and prepares ...Nf6. White has to be careful here because the standard Morra setup with Qe2, Rd1, etc has experienced bad results - Black has smooth development starting with ...Bg4. The best way to meet the Taylor System seems to be 7. O-O Nf6 8. Bf4 - then if 8...Bg4 9. h3 Bxf3 10. Qxf3 shows good compensation for the pawn. Or 8...e6 9. Qe2 often transposes into other systems.
Moving on to a summary of the Bd7 System.
[Event "Morra Gambit Accepted - Bd7 System"]
[ECO "B21"]
[FEN "RNBQKBNR/PPPPPPPP/8/8/8/8/pppppppp/rnbqkbnr b KQkq - 1"]

1.e4 c5 2.d4 cxd4 3.c3 dxc3 4.Nxc3 Nc6 5.Nf3 d6 6.Bc4 e6 7.O-O a6 8.Qe2 Be7 9.Rd1 Bd7   

The Bd7 System isn't very popular nowadays, but above line is Black's most sneaky move order in the system as it avoids dangerous setups with Bg5. Black wants to reduce pressure along the d-file and keep control of the a4-e8 diagonal. But it neglects K-side development and the bishop on d7 can be susceptible to tactics - Rxd7 is a recurring tactical motif.
One common possibility here transposes to a variant of the Classical Main Line with 10. Bf4 e5 11. Be3 Nf6 12. Nd5 - White has good positional compensation.
Moving on to a summary of the Nge7 System.
[Event "Morra Gambit Accepted - Nge7 System"]
[ECO "B21"]
[FEN "RNBQKBNR/PPPPPPPP/8/8/8/8/pppppppp/rnbqkbnr b KQkq - 1"]

1.e4 c5 2.d4 cxd4 3.c3 dxc3 4.Nxc3 Nc6 5.Nf3 e6 6.Bc4 a6 7.O-O Nge7   

This very popular system transfers the knight to g6 from where it controls e5 and prevents Bf4. Of course it's slower than the usual Ng8-f6 and the knight doesn't control d5 or h5. Typical motifs for White include a knight sac on d5, the queen landing on h5, and the pawn push f2-f4-f5.
Moving on to a summary of the Siberian Variation.
[Event "Morra Gambit Accepted - Siberian Variation"]
[ECO "B21"]
[FEN "RNBQKBNR/PPPPPPPP/8/8/8/8/pppppppp/rnbqkbnr b KQkq - 1"]

1.e4 c5 2.d4 cxd4 3.c3 dxc3 4.Nxc3 Nc6 5.Nf3 e6 6.Bc4 Qc7  

This is akin to an accelerated version of the Qc7 system, omitting ...a6. It has a surprise factor, but White has developed a couple of good ideas. One idea is 7. Qe2 meeting 7...Nf6 with 8. e5!? Another idea is 7. O-O Nf6 8. Nb5 Qb8 9. e5! Black must not accept the second pawn, but 9...Ng4 10. Bf4 a6 11. Nd6+ favours White. And 9...a6!? 10. exf6 axb5 11. fxg7 Bxg7 12. Bxb5 keads to a really complex and interesting position.
I will follow-up with a summary of the remaining Morra systems shortly.

31663: <p><a href="https://chess.stackexchange.com/questions/16535/the-strength-of-smith-morra-gambit">Related</a></p>
<p>The Smith-Morra gambit, or the Morra gambit, is where white sacrifices one pawn to get early development while black has not really done anything. This gambit is also used against the Sicilian defense</p>
<pre><code>[FEN &quot;rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR&quot;]
[Title &quot;Morra gambit&quot;]
1. e4 c5 2. d4 cxd4 3. c3 dxc3 4. Nxc3
</code></pre>
<p>What are the pros and cons of using this opening and does the extra pawn black has compensate for the lack of development, also what are white`s plans using this opening?</p>
 1711: <p>I've played and studied the Morra Gambit for several decades, so I hopefully understand it fairly well. I also have an enormous game database and related notebook with themes, ideas, variations, engine analysis, <a href="https://chess.stackexchange.com/questions/38843/is-this-theoretical-novelty-double-piece-sacrifice-actually-sound">theoretical novelties</a>, etc.</p>
<p>The first point to make is that the pros and cons vary a lot depending on your own strength and the strength of your opponents. Playing the Morra at Elo/Glicko 1500 level is <strong>very</strong> different to playing it at 2500 level. The following notes are based on the pros and cons for a player rated around 2000 playing against opponents rated 1800-2300. Other people can answer for lower or higher rating ranges.</p>
<p>Pros:</p>
<ul>
<li>Works well if you want to take your opponent away from his/her main Sicilian repertoire.</li>
<li>Works well if you play the Morra regularly, but your opponent only sees it once a year or less.</li>
<li>Good if you like tactical and uncompromising play because White's better development often leads to a dangerous initiative.</li>
<li>The ability to calculate deeply and accurately is rewarded more often than in most other openings.</li>
<li>Many of the positions that arise from the accepted gambit are difficult for Black to play, especially if s/he isn't familiar with them.</li>
</ul>
<p>Cons:</p>
<ul>
<li>You're a pawn down! So the pressure is initially on White to show justification for that pawn.</li>
<li>You also have to study the Alapin closely because many Black players decline the gambit and forcibly transpose into that variation.</li>
<li>The ability to calculate deeply and accurately is more important than in most other openings.</li>
<li>Requires you to spend lots of time memorising complex variations because Black has a lot of flexibility in responding to the gambit and there is a large volume of theory to study.</li>
<li>If Black has studied at least one defensive line in great detail, <em>you</em> might be the one who runs into nasty variations.</li>
</ul>
<p>Let's start our understanding of the main Morra systems with a summary of the <strong>Classical Main Line</strong>.</p>
<pre><code>[Event &quot;Morra Gambit Accepted - Classical Main Line&quot;]
[ECO &quot;B21&quot;]
[FEN &quot;RNBQKBNR/PPPPPPPP/8/8/8/8/pppppppp/rnbqkbnr b KQkq - 1&quot;]

1.e4 c5 2.d4 cxd4 3.c3 dxc3 4.Nxc3 Nc6 5.Nf3 e6 6.Bc4 d6 7.O-O Nf6 8.Qe2 Be7 9.Rd1 e5  
</code></pre>
<p>This is a solid system characterised by Black's control of d4, prevention of the e4-e5 break (one of White's main tactical motifs in the Morra), and Black's king safety after castling short. White's main compensation is positional - control of d5, a backward pawn weakness on d6, and Black's somewhat passive position. White should focus mainly on active play in the centre and on the Q-side.</p>
<p>Moving on to a summary of the <strong>Qc7 System</strong>.</p>
<pre><code>[Event &quot;Morra Gambit Accepted - Qc7 System&quot;]
[ECO &quot;B21&quot;]
[FEN &quot;RNBQKBNR/PPPPPPPP/8/8/8/8/pppppppp/rnbqkbnr b KQkq - 1&quot;]

1.e4 c5 2.d4 cxd4 3.c3 dxc3 4.Nxc3 Nc6 5.Nf3 e6 6.Bc4 d6 7.O-O a6 8.Qe2 Be7 9.Rd1 Qc7 10.Bf4 Nf6   
</code></pre>
<p>Black moves the queen off the dangerous d-file and strengthens control of the important e5 square. White looks carefully at the e4-e5 break and sacrificing on d5 or b5, while Black typically positions the queen on b8 and tries for the b7-b5 break. This is a dangerous system for Black and has led to many spectacular White victories. But Black should be okay if s/he plays very carefully.</p>
<p>Moving on to a summary of the <strong>Taylor System</strong>.</p>
<pre><code>[Event &quot;Morra Gambit Accepted - Taylor System&quot;]
[ECO &quot;B21&quot;]
[FEN &quot;RNBQKBNR/PPPPPPPP/8/8/8/8/pppppppp/rnbqkbnr b KQkq - 1&quot;]

1.e4 c5 2.d4 cxd4 3.c3 dxc3 4.Nxc3 Nc6 5.Nf3 d6 6.Bc4 a6    
</code></pre>
<p>This system has been quite popular in the past few years. Black protects the b5 square and prepares ...Nf6. White has to be careful here because the standard Morra setup with Qe2, Rd1, etc has experienced bad results - Black has smooth development starting with ...Bg4. The best way to meet the Taylor System seems to be 7. O-O Nf6 8. Bf4 - then if 8...Bg4 9. h3 Bxf3 10. Qxf3 shows good compensation for the pawn. Or 8...e6 9. Qe2 often transposes into other systems.</p>
<p>Moving on to a summary of the <strong>Bd7 System</strong>.</p>
<pre><code>[Event &quot;Morra Gambit Accepted - Bd7 System&quot;]
[ECO &quot;B21&quot;]
[FEN &quot;RNBQKBNR/PPPPPPPP/8/8/8/8/pppppppp/rnbqkbnr b KQkq - 1&quot;]

1.e4 c5 2.d4 cxd4 3.c3 dxc3 4.Nxc3 Nc6 5.Nf3 d6 6.Bc4 e6 7.O-O a6 8.Qe2 Be7 9.Rd1 Bd7   
</code></pre>
<p>The Bd7 System isn't very popular nowadays, but above line is Black's most sneaky move order in the system as it avoids dangerous setups with Bg5. Black wants to reduce pressure along the d-file and keep control of the a4-e8 diagonal. But it neglects K-side development and the bishop on d7 can be susceptible to tactics - Rxd7 is a recurring tactical motif.</p>
<p>One common possibility here transposes to a variant of the Classical Main Line with 10. Bf4 e5 11. Be3 Nf6 12. Nd5 - White has good positional compensation.</p>
<p>Moving on to a summary of the <strong>Nge7 System</strong>.</p>
<pre><code>[Event &quot;Morra Gambit Accepted - Nge7 System&quot;]
[ECO &quot;B21&quot;]
[FEN &quot;RNBQKBNR/PPPPPPPP/8/8/8/8/pppppppp/rnbqkbnr b KQkq - 1&quot;]

1.e4 c5 2.d4 cxd4 3.c3 dxc3 4.Nxc3 Nc6 5.Nf3 e6 6.Bc4 a6 7.O-O Nge7   
</code></pre>
<p>This very popular system transfers the knight to g6 from where it controls e5 and prevents Bf4. Of course it's slower than the usual Ng8-f6 and the knight doesn't control d5 or h5. Typical motifs for White include a knight sac on d5, the queen landing on h5, and the pawn push f2-f4-f5.</p>
<p>Moving on to a summary of the <strong>Siberian Variation</strong>.</p>
<pre><code>[Event &quot;Morra Gambit Accepted - Siberian Variation&quot;]
[ECO &quot;B21&quot;]
[FEN &quot;RNBQKBNR/PPPPPPPP/8/8/8/8/pppppppp/rnbqkbnr b KQkq - 1&quot;]

1.e4 c5 2.d4 cxd4 3.c3 dxc3 4.Nxc3 Nc6 5.Nf3 e6 6.Bc4 Qc7  
</code></pre>
<p>This is akin to an accelerated version of the Qc7 system, omitting ...a6. It has a surprise factor, but White has developed a couple of good ideas. One idea is 7. Qe2 meeting 7...Nf6 with 8. e5!? Another idea is 7. O-O Nf6 8. Nb5 Qb8 9. e5! Black must not accept the second pawn, but 9...Ng4 10. Bf4 a6 11. Nd6+ favours White. And 9...a6!? 10. exf6 axb5 11. fxg7 Bxg7 12. Bxb5 keads to a really complex and interesting position.</p>
<p>I will follow-up with a summary of the remaining Morra systems shortly.</p>
