The three opening principles

The key idea

Center, development, castling — in that order of priority. Every opening move should be explainable by one of the three.

Example 1 · The three principles in the Italian

White and Black apply the three principles as mirror images, with neither one rushing ahead or skipping a step.

1. e4 Principle 1: the center. This pawn controls d5 and f5, and along the way opens the bishop's diagonal and the queen's exit.
2. e5 Black disputes the center with the same move. Nobody gives away that square.
3. Nf3 Principle 2: development, and with a threat — the knight already eyes the pawn on e5.
4. Nc6 Development that also defends. No filler moves.
5. Bc4 The bishop comes out on the diagonal aimed at f7, the weakest point of the enemy king while it's still in the center.
6. Bc5 Black replies with the same idea, eyeing f2.
7. Nc3 Another piece onto the board. Notice what we're NOT doing: we're not touching the same piece twice.
8. Nf6 Black completes its own knight development.
9. d3 A modest pawn with two jobs: it holds e4 and opens the diagonal for the bishop on c1.
10. d6 Same for Black.
11. O-O Principle 3: castle. The king leaves the center before it opens up, and the rook comes in for free.
12. O-O Black closes the same circle. From here on there's no more opening: it's the middlegame, and both sides arrive with their house in order.

Example 2 · The same three principles, another opening

The name changes and the specific plan changes, but the underlying criterion is identical to Example 1.

1. e4 Center again. It doesn't matter what the opening is: the first principle never changes.
2. e5 And black, the same.
3. Nf3 Development with a threat, as always.
4. Nc6 Defense that develops.
5. Bb5 Here the idea changes from Example 1: the bishop isn't aiming at f7, it's pressuring the knight that defends e5. This is the Ruy Lopez — another way of applying the same principle 2.
6. a6 Black asks about the bishop's intentions.
7. Ba4 We keep the pressure. Retreating here breaks no principle: it sustains the idea the piece came out for.
8. Nf6 And they keep developing, attacking e4 along the way.
9. O-O Castling — principle 3 — before anyone complicates the center.
10. Be7 Black does the same with its bishop: room to castle.
11. Re1 The rook enters the file it's going to need as soon as the center moves.
12. b5 Black gains a tempo on the bishop.
13. Bb3 Same idea again: retreating without losing sight of the goal, not a broken principle.
14. d6 They shore up their own center.
15. c3 Typical preparation: this pawn sets up a future d4.
16. O-O And black closes its own castling. Different openings, same three principles — that's what you have to internalize, not the list of moves.

Practice

Your turn with White. Apply the three principles in the order they come: center, development, castling.

1. Center occupied. First principle, done. Start with the center: pawn to e4.
2. Development with a threat — that's how it's done. Now development: knight to f3, attacking e5 along the way.
3. The bishop comes out to the good diagonal. You've almost got all three principles. Bring out the bishop toward the diagonal aimed at f7.
4. Castling. Three principles fulfilled, in the order they were due — and this applies to whatever opening you end up playing. Last step: get your king to safety. Castle.

The three principles, made second nature: center, development, castling. It doesn't matter what opening you end up playing — Italian, Ruy Lopez, whatever — this is the criterion holding it up.