ArcadeWhale
Opening theory is the part of chess that scares beginners away, and it is also the part that matters least at beginner level. Nobody loses a game at 800 rating because they played the wrong sixth move in the Ruy Lopez. They lose because they left a knight hanging on move nine. So this guide is short on lines and long on the three ideas every line is built from.
The three principles
1. Fight for the centre. The four squares e4, d4, e5, d5 are where pieces reach the most of the board. Put a pawn there early — 1.e4 or 1.d4 as White, …e5 or …d5 as Black — and aim your pieces at those squares. A knight on f3 controls e5 and d4; a knight on the rim controls half as much.
2. Develop before you attack. Every move in the first ten should bring a new piece off its starting square: knights first, then bishops, then castle. Moving the same piece twice or bringing the queen out on move three is the most common beginner error, because it feels aggressive and it gets punished by anyone who simply develops with tempo against it.
3. Castle early. The king is a liability in the centre once the files start opening. Castling by move eight or so tucks it behind three pawns and connects your rooks. If you find yourself on move fifteen with the king still on e1, something has gone wrong, whatever the engine evaluation says.
Every good opening is those three principles applied in a particular order. If you forget the moves, play the principles and you will be fine.
Opening 1 — the Italian Game (White)
1.e4 e5 2.Nf3 Nc6 3.Bc4
Centre pawn, knight attacking e5, bishop on the most active diagonal aimed at f7 — the weakest square in Black’s camp, defended only by the king. Follow with d3, Nc3 or c3, O-O, and you have a sound, active position with all three principles satisfied by move six.
What to know: after 3…Bc5 (the Giuoco Piano) play 4.c3 and 5.d4 to build a big centre, or the quieter 4.d3 to keep things solid. After 3…Nf6 do not panic about the attack on e4 — 4.d3 defends it. Avoid 4.Ng5 until you have seen the Fried Liver a few times; it is a knife fight, and beginners cut themselves with it as often as their opponent.
Opening 2 — the London System (White)
1.d4 d5 2.Bf4 (or 2.Nf3 and 3.Bf4)
The London is the opening you play when you want the same structure every game regardless of what Black does: pawns on d4, e3, c3, bishop outside the pawn chain on f4, knights on f3 and d2, castle short. It is nearly impossible to get into trouble in the first ten moves, which is its great strength and its limitation — it teaches patience and piece placement, not tactics.
Play it if you get anxious in sharp positions. Come back to 1.e4 when you want to learn to calculate.
Opening 3 — answering 1.e4 with 1…e5 (Black)
1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 or 3.Bb5 a6
As Black you do not choose the opening, you respond to it, so learn one solid reply to each of White’s main moves. Against 1.e4, the mirror move 1…e5 claims your share of the centre and leads to the positions you are already learning with White. Against 1.d4, 1…d5 does the same job. Against everything else, put a pawn in the centre and develop — the principles are the opening.
Two things to remember as Black: your f7 square is the target of every beginner attack, so keep an eye on the Bc4–Qh5 battery and develop your knight to f6 early to cover it; and do not grab the e4 pawn with your knight on move four unless you have checked what happens after the queen comes to e2 or the rook lands on e1.
The mistakes that actually lose games
Not opening theory. These:
- The early queen. 2.Qh5 and friends win against players who do not know how to answer, and lose tempo after tempo against anyone who develops with attacks on the queen. Learn the refutation (…Nf6 with tempo, …g6, develop) and you will beat it forever.
- Hanging pieces. Before every move, ask what your opponent’s last move attacks. Most games under 1200 are decided by a piece left en prise, not by strategy.
- Moving the same piece twice. Every second move of a developed piece is a move your other pieces do not get.
- Not castling. See principle three.
How to practise
Openings are learned by repetition against a partner who lets you make the same position over and over. A human opponent varies; an engine at a fixed level does not.
Our chess engine has four levels, and they are not the same idea with a bigger number. Level 1 searches one move ahead and then deliberately picks from among moves close to its best, so it makes the kind of mistakes a beginner makes — it leaves pieces where you can take them, and it is there to be beaten while you learn. Level 2 looks two moves ahead and punishes loose pieces. Levels 3 and 4 search deeper and add a quiescence search, which means the tactics that worked earlier stop working and you have to make a real plan.
Play the Italian ten times in a row at level 1. When you stop losing pieces in the first fifteen moves, move to level 2. When your opening no longer decides the game either way, you have learned it — and that is the moment to start caring about the sixth move of the Ruy Lopez.
The move generator is verified against perft, the standard correctness test in computer chess, across 11,024,485 positions, so every move the board allows is a legal one. Click a piece to see its moves: dots for quiet moves, rings for captures.
