(* = A Dan Original/Special Principle)
Also see the video on Opening Principles
The top ten are numbered followed by honorable mentions:
#1 "Move every piece once before you move any piece twice, unless there is a tactic (for either side)" .... Believe it or not, most lower rated players absolutely cannot follow this guideline no matter how hard they try! They unfortunately "have a better idea" than to follow this long-lived advice.
#2 "It is usually MUCH better to take a piece that is doing nothing and make it do something than it is to take a piece that is already doing something and make it do a little more!"
#3"Develop the pieces on the side you are going to castle before the pieces on the other side." or as a corollary, "Develop the bishop on the side you wish to castle before the other bishop."
#4 Don't develop your pieces to squares where they can just be efficiently attacked by enemy pieces of lesser value (often pawns) and therefore have to retreat.
#5 "Castling is usually the most important move in any opening." It is the only move which may save a tempo by moving two pieces at once!
#6 "If your opponent plays something you don't know, don't panic - just follow the general principles (like the ones on this page!)"
#7 "Develop knights before bishops." (Note: This usually means the Knight before the bishop on the same side, not necessarily both Knights before both bishops).
#8 "Don't play the opening like the middlegame."
#9 "The player who uses his Rooks best probably wins the opening." Alternately, "The main goal of the opening is to properly develop your rooks."
#10 "Don't block your break moves with pieces" (e.g. "Don't put your knight in front of your c-pawn in double d-pawn openings") and "Put your rooks behind your break moves."
Hon. Mention: Play the moves you have to play before the moves you want to play
Hon. Mention: "Develop a rook to the same file where you opponent has his queen, especially if the queen has already moved. This even makes sense if the file is currently closed, so long as there is any possibility it could open up due to exchanges."
Hon. Mention: "Don't start a fight until either all your pieces are ready or at least you have a lot more pieces active than your opponent."
Hon. Mention: *"Don't start a fight until your king is safe!!" (especially if your opponent's king is already safe) or "Don't fool around until you are castled." or "Don't start a fight in the center if you are not castled; especially if the opponent is castled."
Hon. Mention: "If you are White and your opponent does not stop you by his opening moves, set up the 'little center': e4 and d4". After 1.e4 on 14 of Black's 20 replies the main second move is 2.d4 (except after 1...e5, 1...c5, 1...Ng6, 1...d5, 1...f5, and 1...b5).
Hon. Mention: "Play the piece to the square where you KNOW it must go before you play another piece to the square where you think it might go. The extra move might help you determine to which square the latter piece should move."
Hon. Mention: "Moving just two pawns in the opening is usually not enough to give your pieces space; on the other hand, moving six or more pawns is usually too weakening and takes too much time."
"Low rated players should play tactical openings to improve their tactics."
"The king always moves two when you castle."
"The best way to refute a gambit is to accept it."
"A good metric is how many moves it takes for you to move all your non-pawns. 12-16 is normal. If you use a lot more than that, you are probably neglecting your development, likely your Rooks."
"In the opening, if you can drive a knight out of the center by attacking it with a pawn, it is usually correct to do so."; similarly, ""If you can push a pawn up and safely drive a knight out of the center, it is probably good to do so, especially if in doing so you don't weaken any squares."
*"Any opening that you know well is good no matter what its reputation."
"For most players, it is not memorizing opening sequences that are important, but following good general principles that apply throughout the game and especially those in the opening." Of course, the stronger you get, the more specific opening knowledge is helpful.
*"It is good for most developing players to play the King's Indian Defense and the French Defense for a while, since you cannot avoid their pawn structures in many irregular openings anyway."
"In the Ruy Lopez, the play is rich enough that the better player almost always wins."
"Until you can develop ALL your pieces every game during the opening, you are not ready for intermediate play."
*"Bd2 is often a bad place to develop White's queen's bishop in most openings unless it is tactically required."
"Don't use a bishop to pin the adverse king's knight to the queen (Bg5 for White; Bg4 for Black) before the opponent has castled." (One of Lasker's rules)
Corollary: If a bishop does pin a knight to the queen and "BxN" is not a threat, then it is usually correct to immediately play "P-R3" (...h6 or h3) to "put the question to the bishop" to find out where it wants to go and lower the opponent's flexibility.
"Don't play your f-pawn up one (f3/f6) unless your opponent's queen is off the board, you are already castled, or are soon going to castle the opposite side. Especially avoid guarding the e-pawn from a pawn capture, e.g. 1.e4 e6 2.d4 d5 3.f3?! dxe4 4.fxe4?? Qh4+ 5.g3?? Qxe4+ and 6...Qxh1.
"Don't prevent pins with h3/h6 and a3/a6 unless those are the only good squares for the bishop; on the other hand, playing h3/h6 to prevent a knight from harassing a Bishop on e3/e6 is often correct."
"If a Bishop plays Bg5/g4 and is NOT threatening to take a knight (it can do so, but it is not a threat), it is often correct to hit it with ...h3 or ...h6 to force it to decide which diagonal it is going to stay on."
"Don't move all pawns onto the same color squares as this creates weak squares of the opposite color."
"The more "closed" the opening, the more you want to put your pieces behind your pawns. The more open the opening, the more putting pieces in front of your pawns is OK. So "Put your pieces on the 'right' side of the pawns (usually meaning behind them!). For example, in non e-pawn (and many e-pawn openings, like the Ruy Lopez) openings, it is usually right to put your queen's knight behind your c-pawn, like c4/Nc3 or ...c5/...Nc6."
"A premature attack is doomed to failure."
"If you opponent is castled and you are not, be especially aware about catching up in development, especially castling too, and not prematurely opening the center to his (big) advantage."
"If you castle opposite sides and queens are still on the board, the side that gets to the opponent's king first with the most usually wins!" (This principle is true more often when the center is at least stable, if not fixed."
"If you are already winning, try to castle on the same side as your opponent. Castling opposite sides tends to make the game sharp and minimize any material advantage."
If you move a pawn to open up a diagonal for a bishop, then should you usually NOT move up another pawn to develop the bishop on the other diagonal. It should be developed on the original diagonal without wasting time to push the second pawn.
Don't fall too far behind (in development) in the ability to castle. In particular, if you are opponent has the ability to castle or has already, make sure you can get your king out of the center too before it is caught in a crossfire of centralized rook checks.
Botvinnik's Rule: In slow games, use about 20% of your time for the first 15 moves. In fast games, use LESS than 20% of your time for the first 15 moves;
Botvinnik's rule would not apply in exceptionally tactical openings, ones where you get out of the book in one or two moves, or of course ones that go book for (almost) 15 moves.
The Three Main Opening Goals (not to be confused with principles):
Also see the video on Opening Principles
The top ten are numbered followed by honorable mentions:
#1 "Move every piece once before you move any piece twice, unless there is a tactic (for either side)" .... Believe it or not, most lower rated players absolutely cannot follow this guideline no matter how hard they try! They unfortunately "have a better idea" than to follow this long-lived advice.
#2 "It is usually MUCH better to take a piece that is doing nothing and make it do something than it is to take a piece that is already doing something and make it do a little more!"
#3"Develop the pieces on the side you are going to castle before the pieces on the other side." or as a corollary, "Develop the bishop on the side you wish to castle before the other bishop."
#4 Don't develop your pieces to squares where they can just be efficiently attacked by enemy pieces of lesser value (often pawns) and therefore have to retreat.
#5 "Castling is usually the most important move in any opening." It is the only move which may save a tempo by moving two pieces at once!
#6 "If your opponent plays something you don't know, don't panic - just follow the general principles (like the ones on this page!)"
#7 "Develop knights before bishops." (Note: This usually means the Knight before the bishop on the same side, not necessarily both Knights before both bishops).
#8 "Don't play the opening like the middlegame."
#9 "The player who uses his Rooks best probably wins the opening." Alternately, "The main goal of the opening is to properly develop your rooks."
#10 "Don't block your break moves with pieces" (e.g. "Don't put your knight in front of your c-pawn in double d-pawn openings") and "Put your rooks behind your break moves."
Hon. Mention: Play the moves you have to play before the moves you want to play
Hon. Mention: "Develop a rook to the same file where you opponent has his queen, especially if the queen has already moved. This even makes sense if the file is currently closed, so long as there is any possibility it could open up due to exchanges."
Hon. Mention: "Don't start a fight until either all your pieces are ready or at least you have a lot more pieces active than your opponent."
Hon. Mention: *"Don't start a fight until your king is safe!!" (especially if your opponent's king is already safe) or "Don't fool around until you are castled." or "Don't start a fight in the center if you are not castled; especially if the opponent is castled."
Hon. Mention: "If you are White and your opponent does not stop you by his opening moves, set up the 'little center': e4 and d4". After 1.e4 on 14 of Black's 20 replies the main second move is 2.d4 (except after 1...e5, 1...c5, 1...Ng6, 1...d5, 1...f5, and 1...b5).
Hon. Mention: "Play the piece to the square where you KNOW it must go before you play another piece to the square where you think it might go. The extra move might help you determine to which square the latter piece should move."
Hon. Mention: "Moving just two pawns in the opening is usually not enough to give your pieces space; on the other hand, moving six or more pawns is usually too weakening and takes too much time."
"Low rated players should play tactical openings to improve their tactics."
"The king always moves two when you castle."
"The best way to refute a gambit is to accept it."
"A good metric is how many moves it takes for you to move all your non-pawns. 12-16 is normal. If you use a lot more than that, you are probably neglecting your development, likely your Rooks."
"In the opening, if you can drive a knight out of the center by attacking it with a pawn, it is usually correct to do so."; similarly, ""If you can push a pawn up and safely drive a knight out of the center, it is probably good to do so, especially if in doing so you don't weaken any squares."
*"Any opening that you know well is good no matter what its reputation."
"For most players, it is not memorizing opening sequences that are important, but following good general principles that apply throughout the game and especially those in the opening." Of course, the stronger you get, the more specific opening knowledge is helpful.
*"It is good for most developing players to play the King's Indian Defense and the French Defense for a while, since you cannot avoid their pawn structures in many irregular openings anyway."
"In the Ruy Lopez, the play is rich enough that the better player almost always wins."
"Until you can develop ALL your pieces every game during the opening, you are not ready for intermediate play."
*"Bd2 is often a bad place to develop White's queen's bishop in most openings unless it is tactically required."
"Don't use a bishop to pin the adverse king's knight to the queen (Bg5 for White; Bg4 for Black) before the opponent has castled." (One of Lasker's rules)
Corollary: If a bishop does pin a knight to the queen and "BxN" is not a threat, then it is usually correct to immediately play "P-R3" (...h6 or h3) to "put the question to the bishop" to find out where it wants to go and lower the opponent's flexibility.
"Don't play your f-pawn up one (f3/f6) unless your opponent's queen is off the board, you are already castled, or are soon going to castle the opposite side. Especially avoid guarding the e-pawn from a pawn capture, e.g. 1.e4 e6 2.d4 d5 3.f3?! dxe4 4.fxe4?? Qh4+ 5.g3?? Qxe4+ and 6...Qxh1.
"Don't prevent pins with h3/h6 and a3/a6 unless those are the only good squares for the bishop; on the other hand, playing h3/h6 to prevent a knight from harassing a Bishop on e3/e6 is often correct."
"If a Bishop plays Bg5/g4 and is NOT threatening to take a knight (it can do so, but it is not a threat), it is often correct to hit it with ...h3 or ...h6 to force it to decide which diagonal it is going to stay on."
"Don't move all pawns onto the same color squares as this creates weak squares of the opposite color."
"The more "closed" the opening, the more you want to put your pieces behind your pawns. The more open the opening, the more putting pieces in front of your pawns is OK. So "Put your pieces on the 'right' side of the pawns (usually meaning behind them!). For example, in non e-pawn (and many e-pawn openings, like the Ruy Lopez) openings, it is usually right to put your queen's knight behind your c-pawn, like c4/Nc3 or ...c5/...Nc6."
"A premature attack is doomed to failure."
"If you opponent is castled and you are not, be especially aware about catching up in development, especially castling too, and not prematurely opening the center to his (big) advantage."
"If you castle opposite sides and queens are still on the board, the side that gets to the opponent's king first with the most usually wins!" (This principle is true more often when the center is at least stable, if not fixed."
"If you are already winning, try to castle on the same side as your opponent. Castling opposite sides tends to make the game sharp and minimize any material advantage."
If you move a pawn to open up a diagonal for a bishop, then should you usually NOT move up another pawn to develop the bishop on the other diagonal. It should be developed on the original diagonal without wasting time to push the second pawn.
Don't fall too far behind (in development) in the ability to castle. In particular, if you are opponent has the ability to castle or has already, make sure you can get your king out of the center too before it is caught in a crossfire of centralized rook checks.
Botvinnik's Rule: In slow games, use about 20% of your time for the first 15 moves. In fast games, use LESS than 20% of your time for the first 15 moves;
Botvinnik's rule would not apply in exceptionally tactical openings, ones where you get out of the book in one or two moves, or of course ones that go book for (almost) 15 moves.
The Three Main Opening Goals (not to be confused with principles):
- Activate all your pieces safely, efficiently, and effectively
- Get as much center control as possible (occupation is not always necessary)
- Find a safe place for your king and get it there as quickly as possible