Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nc6

Normal Variation
	a b c d e f g h 8 7 6 5 4 3 2 1 8 7 6 5 4 3 2 1 a b c d e f g h
	Position in Forsyth-Edwards Notation (FEN) r1bqkbnr/pppp1ppp/2n5/4p3/4P3/5N2/PPPP1PPP/RNBQKB1R
	Moves: 1. e4 e5 2. Nf3 Nc6
	Parent: King's knight opening
	Responses: ; 3. Bb5 · Ruy Lopez; 3. Bc4 · Italian Game; 3. d4 · Scotch Game; 3. Nc3 · Three Knights Opening; 3. c3 · Ponziani Opening;

2...Nc6 · Normal variation

2...Nc6 is the natural and most common move, combining defence of the pawn with control of the d4 square. Black avoids committing another pawn for now. This is the most common position after two moves in chess.

White has several choices for how to reply, which lead to very different games.

Develop a piece

White usually decides to develop the bishop next. While the usual advice is to "develop knights before bishops", by holding off on Nc3, White retains the option of playing c3 and d4 to take over the centre with pawns.

3. Bb5, known as the Spanish or Ruy Lopez, is the most popular^[1] and theoretical continuation. By pressuring Black's knight, White is indirectly threatening e5 which the knight defends. This usually leads to tough, positional game. The mainline is 3...a6, but there are many viable continuations all intensely studied.

3. Bc4, the Italian game, develops the bishop to target Black's vulnerable f7 pawn instead. This is the second most common move, though more common in amateur games^[2]. Most commonly Black plays 3...Bc5, the Giuoco piano, or 3...Nf6, the Two knights defence.

3. Nc3, the Three knights opening, is reached if White decides to develop their knight next after all. This is a quieter (read: drawish) continuation. White will have a hard time playing d4 in the future. Black usually plays 3...Nf6, reaching the Four knights.

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Spanish game

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Italian game

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Three knights game

Contest the centre

White can prioritise contesting the centre with pawns.

3. d4, the Scotch opening, busts open the centre straight away. This is the third most common continuation. After Black captures 3...exd4, White can recapture the pawn or gambit it for development.

3. c3, the Ponziani opening, prepares d4 with the c pawn. White would like to not just to put a pawn on d4 but keep one there. This is an uncommon continuation.

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Scotch game

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Ponziani opening

Offbeat continuations

The above five replies cover almost every serious games. A few very offbeat choices make up less than one percent of games combined. The ideas include:

Developing the king's bishop somewhere else: 3. Be2?!, the Tayler opening, 3. Bd3, or 3. g3 in order to play 4. Bg2, the Konstantinopolsky opening.
A flank move, 3. c4, the Dresden opening, to control d5 and allow the b1 knight to develop behind the pawn.
3. d3, an unnecessarily timid reply that avoids contesting the centre and voluntarily cramps White's position.

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Konstantinopolsky opening

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Tayler opening

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Dresden opening

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3. d3

Bad moves

Some dubious gambits:

3. Nxe5?? is the Irish gambit. White sacrifices a knight to take over the centre uncontested, but the cost of being a minor piece down is vastly more punishing.
3. b4?, the Pachman wing gambit, where White sacrifices the b pawn to give Black a hand in development (3...Bxb4). If Black is equally generous (3...Nxb4? 4. Nxe5) it's at best an even game.

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Irish gambit

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Pachman wing gambit

Theory table

For explanation of theory tables, see theory table and for notation, see algebraic notation..

1. e4 e5 2. Nf3 Nc6

	3	4	5
Ruy Lopez	Bb5 a6	Ba4 Nf6	O-O Be7	=
Italian Game	Bc4 Bc5	c3 Nf6	d4 exd4	=
Scotch Game	d4 exd4	Nxd4 Bc5	Nb3 Bb4+	=
Four Knights Game	Nc3 Nf6	d4 exd4	Nxd4 Bb4	=
Ponziani Opening	c3 d5	Bb5 dxe4	Nxe5 Qg5	=