Opening principles
Opening principles are general guidelines for the first moves: control the center, develop knights and bishops quickly, castle early and avoid moving the same piece twice without reason.
Also called: principles of the opening
Opening principles are simple rules of thumb that guide you when you do not know the theory. The main ones are to take or influence the center with pawns and pieces, to bring out the knights and bishops, to castle for king safety, and to connect the rooks. They also warn against moving the same piece several times, bringing the queen out too early and making many pawn moves without a plan.
The reason behind each rule is speed. Development means more pieces take part in the game sooner, central control gives your pieces room to move, and castling protects the king and brings a rook into play. A side that follows them well usually has a harmless position and options. The side that ignores them often loses time and suffers when the position opens.
The example shows the position after a short sequence that follows these ideas. Both sides put a pawn in the center, bring out minor pieces and castle by move five. Nothing flashy happens, yet White already has two minor pieces out, Black has three, and both kings are castled.
Principles are not laws. A good player breaks one when concrete play demands it, for example by moving the queen early to win material or by delaying castling to attack. The mistake is breaking a principle without a concrete reason, so before you do, check what the opponent can do in reply.
Also worth reading is Catalan setup. The Catalan setup is a White formation with pawns on d4 and c4 and a fianchettoed bishop on g2, putting long-term pressure on Black's center and the queenside along the long diagonal.
It sits close to Early queen move. An early queen move is bringing the queen out in the first few moves, before the minor pieces are developed, which usually loses time because the opponent can attack it with developing moves.
Compare it with Fool's mate. Fool's mate is the quickest checkmate possible: Black mates on the second move with Qh4 after White has pushed the f and g pawns, which leaves the king's diagonal wide open.
Opening ideas such as "Opening principles" are easier to keep when they are tested on your own games, which is what a first lesson with George Li begins with.
Related terms
Development means bringing your pieces from their starting squares to active posts, usually by moving the knights and bishops out, castling and linking the rooks, so they can all contribute to the fight.
Center control means influencing the central squares d4, d5, e4 and e5, with pawns, pieces or both, so that your forces move freely and the opponent has less room to operate.
A tempo is a single move counted as a measure of time: gaining one means making a useful move that also forces the opponent to react, while losing one means spending a move that accomplishes nothing.
King safety is the degree to which a king is protected from attack, as determined by its pawn cover, the defenders nearby, the open lines pointing at it and how quickly the opponent can bring attackers to the area.
An early queen move is bringing the queen out in the first few moves, before the minor pieces are developed, which usually loses time because the opponent can attack it with developing moves.
Castling is a special king move that shelters the king and activates a rook in one turn: the king goes two squares toward an unmoved rook, which then jumps to the king's other side.
Guides that go further
Most popular chess openings and win rates
The most played openings, how often White wins, and how the numbers change with rating, computed from public games.
What to decide first, the questions to ask, what a first lesson should show and the red flags to avoid.
A game review, a read on your level and a written study plan from George Li.
Want to spot this in your own games?
A first lesson starts with your games: George reviews them and builds a study plan around what he finds.