The Online Chess Glossary for Kids and Parents

Clearance/Clearance Sacrifice

• Clearance or a Clearance Sacrifice is a term used to describe a breakthrough (see "breakthrough") of some kind. This means that you have captured (see "capture") one of your enemy's pieces, and when you captured, you busted (see "bust") open the position for the rest of your pieces to attack (see "attack"). In this case, a Clearance Sacrifice (see "sacrifice") means that you gave up some material in order to blow open the position and make way for the rest of your pieces to get in the game.

Clock/Chess Clock

• A clock or chess clock is a timer. Either an analog (see "analog clock") or digital (see "digital clock") clock is used to track how much time is being used for the game. It is typical for a chess tournament to require the use of a chess clock, as this helps the players keep track of their time. If a player "runs out of time on the clock" during a chess game, he/she will "lose that game on time". The only situation where a player would not lose the game on time if he/she ran out of time on the chess clock, would be a case of Insufficient Losing Chances (see "Insufficient Losing Chances").

Closed File

• A file (see "file") that has both black and white pawns on it.

Closed Game

• A closed game is one with a locked pawn structure and few open files (see "open files" and "files") or diagonals (see "diagonals").

Combination

• A combination is a series of forcing moves which leads to a favorable outcome.

•  For example, you play a move. Your opponent's response (perhaps a recapture) is forced. You then play a move which attacks your opponent's king and rook, winning the rook. Finding simple combinations like this is an important part of chess.

Compensation

• A benefit you get for a sacrifice ("see sacrifice") of some kind. For example, if you sacrifice a bishop for two pawns and an attack (see "attack") on the king, your compensation for the sacrificed material is the attack on the king.

Connected Passed Pawn

• (See "passed pawns"). The term, connected passed pawns, sometimes referred to as "connected passers" refers to a pair (which means two) of connected passed pawns. This means that a player possesses two passed pawns, and these passed pawns are "connected" on two adjacent files ("see files"). For example,if a player had a and b pawns, and they were both passed, this would mean that he/she had "connected passed pawns".

Consolidate/Consolidation

• To consolidate is to make your position solid again. You often need to consolidate after you have won material or accepted a sacrifice.

Counterplay

• Counterplay occurs when you are in a worse position, but you can create threats (see "threat") that make it harder for your opponent to win the game. Creating counterplay is an important part of good defense.

Cramped

• A cramped position does not have enough space to accommodate a player's pieces. Usually the right strategy is to exchange pieces. The player will still lack space but may not be cramped.

Critical Position

• The term "Critical Position" means that you have reached the moment in the game where every move you and your opponent make could determine the "result" (meaning who wins) the game. The "critical position" is considered to be one of the most, if not the most, important moment in the game and it is usually the move where both players will take a lot of time on their chess clock (see "clock").

Decline

• To decline something is to not take it. For example, a player might decline a sacrifice or a draw offer.

Decoy

• A decoy is a distraction. Often a player might use a decoy to get his/her opponent (see "opponent") to think about something else, while the player is actually threatening (see "threat") something else. A decoy is a type of tactic (see "tactic").

Defense/Defending

• To play defense, or defend, is to protect. One might "defend" a pawn with a piece, or you might "play defense on the kingside (see "kingside")" in order to stop your opponent's threats on that side of the board. By moving your pieces into position to guard and protect either a piece or a square, you are defending.

Deflection

• A tactic which distracts an opponent’s piece from its duty, such as defending a piece or a key square.

• Demolition means to break something up, such as the pawn structure around the opponent’s king. 

• A more old-fashioned form of chess notation (see "notation"). Moves that the players make are written down "descriptively", rather than by using letters and numbers to point to the squares on the board. For example, "B-KN3" means "bishop to the king knight's third square"; the "king knight's third square" is the third square up from where the king's knight started out. In the more commonly used algebraic notation (see "algebraic notation") that move would be written "Bg3". Descriptive notation is generally considered to be more confusing and is rarely used anymore.

• In a situation where a piece is going to be captured (see "capture") anyway, that piece may try to take out any enemy piece, even just a pawn. This tactic (see "tactic") often happens when both sides have pieces under attack; both sides pieces are going to be lost, so one (or sometimes both) players try to get at least something for their piece.  

• To develop is to bring one’s pieces out from their starting positions. If you have a lead in development, you have more pieces off of their starting squares and in the game than your opponent.

Deviate

• To deviate is to play something other than the main line (see "main line" and also see "sideline"). If a player deviates in the opening, he or she is playing something that is not common or expected.

• A line of squares, which are all one color (either white or black) going both up and over at the same time. For example, there is a diagonal going from the bottom left corner (a1) to the top right corner (h8). This is one of the two "long diagonals". Bishops and queens move along diagonals.

Diagram

• A diagram is a picture taken of the chess board while the pieces are setup in a particular position. While reading any one of our educational articles here on ChessKid.com, you will likely come across diagrams of the chess board designed to help you learn more about the different strategies (see "strategy") of chess.

• A chess clock which runs on electricity. Digital clocks are more accurate than wind-up analog clocks and can have delay or increment.

• An attack which happens when an attacking piece moves out of the way, opening a line for another attacking piece to threaten the opponent. Imagine a white knight in front of a white bishop, which is pointed at a black queen. The white knight moves out of the way, opening the way for the bishop to threaten to take the black queen. This is a discovered attack. A discovered check is the same thing, but the threatened piece is the king, so it is a check. You can learn more in our chess term on discovered attacks.

• An attack on two things at once. This often happens as a result of a fork (see "fork") or discovered attack (see "discovered attack"). The advantage of a double attack is that it is hard for the defender to defend two things with one move, so he/she might lose one of the pieces.

• A check by two attacking pieces at the same time. This always happens as a result of a discovered check (see "discovered check"). Imagine a black rook pointed at a white king, with a black knight in between. The knight moves, putting the white king in check, and also opening the way for the black rook to check the king. So the king is in check by both the knight and the rook at the same time. This is double check.

• Two pawns of the same color which stand one in front of the other [on the same file (see "file")]. Since pawns all start off next to each other, each on a different file, the only way for two pawns of the same color to get to the same file is by capturing (see "capture"). Doubled pawns are often a weakness (see "weakness"), since they cannot protect each other and also cannot move as easily (one might be blocking the other).

• A draw is a tie game. In the case of a draw, nobody wins. If you are playing in a tournament, you and your opponent each get half a point for a draw. If one of you wins, they get the whole point, and the loser gets no points.

• When one player asks his/her opponent to agree to a tie game. A player may "offer a draw" when the position is very equal (nobody has much chance to win) or for various other reasons. The opponent who receives a draw offer can either accept it (see "accept"), in which case the game is a draw; or decline it (see "decline"), in which case the game continues.

Dynamic

• In chess, dynamic means active. A dynamic position is one with a lot of active pieces for both players.

• Short for "Encyclopedia of Chess Openings", a book which is constantly being updated and which lists all the openings (see "opening") and shows many ways the game can go at the start. It gives thousands of variations (see "variation") and analysis (see "analysis") describing what the authors think of them. It also has a coding system which allows chess players to look up the starting moves by a number, such as "B78" (which is a ECO Code for the Dragon Sicilian, a particular type of opening).

• A number which describes a chess player's level of skill, on a scale from 100 to about 3000. (See "rating"). The system was invented by Arpad Elo; the player's Elo rating goes up if he/she wins, and down if he/she loses. More points are gained by beating a higher-rated player, and more points are lost by losing to a lower-rated player. 

• En passant is a special rule that allows pawns to capture (see "capture") enemy pawns which try to skip by them. If an enemy pawn moves two squares in one turn and lands next to one of your pawns, it can be captured as if it had only moved one square. An en passant capture must be played on the move immediately after the enemy pawn moves or the right to capture en passant is lost. 

• French for "in take"; it means a piece which can be captured (see "capture") by the opponent. For example, if a knight is attacking a queen, that queen is said to be en prise.

• The Encyclopedia of Chess Openings, also called ECO, is a book that lists all the known openings that have been played in chess games. The Encyclopedia of Chess Openings contains thousands of variations with analysis and opinions by top experts who play the opening. ECO uses a code to identify each opening. For example, B78 is the ECO code for the popular opening variation, the Sicilian Dragon. 

• The last part of the game, which takes place after the middlegame (see "middlegame"). The endgame is generally believed to start when most of the pieces have been traded, especially if the queens are traded. Usually, in the endgame, it is not possible to start a mating attack, and players instead try to win material (see "material") or promote a pawn (see "promotion"). 

• When nobody has an overall advantage. The players may each have their weaknesses (see "weakness"), well-placed or badly-placed pieces, or even different amounts of material (see "material"); but if it all balances out, that is called "equality".

• When each player captures a piece of the same value from the opponent. Example: "Jon captured Betty's knight, and then Betty captured Jon's knight. The two players exchanged knights, and nobody gained any points of material."
• A rook against a bishop or knight is called "the exchange". If you win a rook for one of your minor pieces (see "minor piece") you have "won the exchange", and your opponent "lost the exchange". If you have a rook against a minor piece, you are "up the exchange".

• To let your opponent take a rook in return for a minor piece (see "minor piece") is to make an exchange sacrifice. Since a rook is worth more points than a knight or bishop, you lose points by making an exchange sacrifice; that is why it is a sacrifice (see "sacrifice").

Evaluate/Evaluation

• To evaluate a position in chess is to decide who you think has the better position—White or Black. Your coach might give you a position to solve in which you are asked to evaluate the position and determine which move is best. That means you should decide who stands better and by how much. Then you should find a strong move that improves the evaluation for your side.

• To fianchetto is to develop a bishop to b2 or g2 (or b7 or g7 for Black) after advancing a knight's pawn. For example, White could begin with a fianchetto by playing 1.g2-g3 and 2.Bf1-g2.

• The French acronym for the “Federation Internationale des Echecs,” this is the world governing body of chess and is often referred to as either FIDE or the World Chess Federation.

• A master-level chess player who has reached the international Elo rating (see "Elo Rating") of 2300. This is the title which is beneath the titles of Grandmaster and International Master.

• The rule which says that the game is a draw if there have been no captures or moves by pawns (for either side) in the last fifty moves of a game. This is to keep games from going on forever when neither player is making any progress. For example, if you have king and rook against a king and rook, you can play that for fifty moves, but if neither side loses a rook or gets checkmated, then it will be a draw. If a rook gets captured, the count would start again.

• An up-and-down (vertical) line on the chessboard. Rooks and queens can move along the files, which are called by letters in algebraic notation (see algebraic notation), for example, the "a-file", the "b-file" and so on.

• An unkind word for a bad chess player. See also "patzer".

• A position in which the players' center pawns are locked together and unable to move.

• To flag means to lose on time. The word comes from older chess clocks (see "chess clock") that have a small flag that falls when one is out of time.

• The side of the board (see also "wing"). Not the center. 

• The fastest possible way to get checkmated, also known as the "two-move checkmate". This happens when White moves his/her f- and g-pawns in the first two moves, allowing Black to come down with the queen and give checkmate on the h4 square.

• A file which has only one side's pawn on it. So it is "open" for the side which does not have a pawn, and he/she can use it for the rooks. See also "open file" and "file". 

• A piece that can be taken for free (see also "en prise"). For example, if a rook is being threatened by a pawn, that rook is said to be hanging, no matter whose move it is.

• Two of one side's pawns, standing side-by-side, with no other pawns of the same color on either side of them. For example, if White has pawns on d4 and c4, and no pawns on the b- or e- files, then he/she has hanging pawns.

• A rook or a queen; see also "major piece".

Helper Mate

• A checkmate (see "checkmate") in which a piece attacking the king is defended by a "helper." The queen and helper mate, in which the queen attacks the king from up close with the support of a defensive helper, is the most common type of checkmate.

• A square, usually in the opponent's side of the board, that can never be protected by a pawn. Holes make great posts (see also "outpost") for your pieces, especially knights. 

• An opening strategy that does not try to occupy the center (see "center") with pawns. Instead, the hypermodern strategy tries to control the center with pieces from the flanks.

• An increment is time a player receives when they complete a move. For example, both players might start with 90 minutes, but when they move, they might get another 30 seconds. The 30 seconds added is the increment.

• A group of openings that are usually reached by Black meeting the move 1.d4 with 1...Nf6. This includes all defenses to the main 1.d4 openings except for the Queen's Gambit.

• The player with the initiative is the one who is creating threats. It is usually good to have the initiative because your opponent may easily make mistakes while trying to defend against your threats.

• A rule which allows a player to claim that his/her opponent does not have a realistic chance to win on the board and is only trying to win on time. This is to prevent players from playing a totally drawn position to try to win on time. You can only make this claim if you have less than five minutes and if there is no delay on the clock (see "time delay"). The tournament director (see "tournament director") has to decide if the game should be a draw, if it should keep going as it is, or if you should switch to a clock with delay.

• When there is not enough material left on the board to create a checkmate, then it is an automatic draw. For example, if there are only two kings left, that is insufficient material, since there is no way to checkmate, so the game is an immediate draw. Also, if there is only a king against a king and bishop or king and knight, that is also insufficient material, since a lone bishop or knight cannot checkmate.  

• Interference is a tactic in which a line is closed, usually by a sacrifice, and the defender is cut off.

• International Master (abbreviated IM) is the second-highest title in chess. To become an IM, you must reach an Elo rating of 2400 and make three international master norms (see "norm").

• To move a piece between an attacking piece and a piece that is attacked.

• A sort of "feeling" about what might be the best move or plan in a position. Intuition is something that a player develops from the experience of playing similar positions. Intuition makes it possible to "guess" what might be the best move without calculating (see "calculate/calculation") everything. 

Invitational Tournament

• A chess tournament that players are only allowed to compete in if they have been invited to play. 

• An opening (see "opening") with a very uncommon move in the first few moves. Openings that begin with pawns on the wing are often irregular. 

• A pawn which does not have any other pawns of the same color on the files on either side of it. For example, if white has a pawn on d4 and no pawn on the c- or e- files, then he/she has an isolated pawn. This can be a disadvantage, since it cannot be guarded by pawns, so pieces might get stuck guarding it.

• French for "I adjust" (see "adjust"). If a piece is sitting a little bit out from the center of a square on the chessboard, you may want to fix it. But according to the touch move rule you would have to move any piece you touch. So you need to say "I adjust" before fixing the piece. Many players say "J'adoube", since this is understood by chess players everywhere.

• To talk about a game which you are watching, in such a way that the players can hear. This is a very bad thing to do if it is a serious game, and probably not very polite if it is a casual game. Sometimes kibitz is used to describe people who are just watching a game and not saying anything.

• An attack (see "attack") on the king which involves the king being chased out of its home and going on a long journey, trying to escape from enemy pieces. Sometimes a king can be chased all the way into the opponent's half of the board in a king hunt.

• The side of the board where the king starts out. For White, this is the right-hand side of the board; for Black, it is the left-hand side. The kingside includes the e-, f-, g-, and h-files.

• A knight on the side of the board (one of the wings). Usually it is better to have your knights in the center (see "center") of the board, where they have more mobility (see "mobility") and can reach more important squares. So a knight on the rim is often in a bad position. There is a famous saying that rhymes "a knight on the rim is dim", meaning that the knight on the side of the board is not very good.

• Liquidation is trading pieces. Players often liquidate by making many equal trades to reach an endgame (see "endgame"). Liquidation is a good way to use a material advantage (see "advantage" and "material") or escape an attack. See "attack." 

• The long diagonal stretches from one corner of the board to the opposite corner. There are two longest diagonals on the board. One starts on the square a1 and goes to h8; the other starts on h1 and goes to a8.

• The Lucena Position is well-known in endgame theory. One side has a king, rook, and pawn; the other has a king and rook. The side with the pawn can win using a method called “building a bridge” or the "Lucena Method” to escape the defender’s attempt to give perpetual check.  

• Luft means “air” in German. In chess, this means making an escape square for your king by pushing one of the pawns in front of the castled position. This purpose of "making luft" is to avoid being checkmated (see "checkmate") on the back rank (see "back rank").

• The most commonly played moves in an opening (see "opening"). An opening variation that has been played a lot and is very popular. Example: "The game followed a main line. So many players had already played the first fifteen moves before." 

• A rook or queen. These are the most powerful pieces, able to checkmate on their own needing only the help of their king. Compare to "minor piece": a knight or bishop.

• A greater number of pawns on one side of the board, whether the kingside, queenside, or center. A majority can be used to make a passed pawn (see "passed pawn").

• A series of moves by one or several pieces with the goal of improving their position(s) on the board. Usually these are quiet moves without tactical threats. Example: "Billy used a maneuver to bring his knight to the strong outpost square."

• A player who is considered to have reached a certain level of achievement in chess. You can become a "national master" by achieving an ELO rating over 2200; internationally there are the FIDE Master, International Master, and Grandmaster titles, which require higher achievements.

• A series of games played between two opponents. Matches are often held to determine the champion of something, like a city, school, or the world!

• Short for "checkmate". The end of the game, where a king is in check and has no way to get out of check. See "checkmate".

• The pieces and pawns (not counting the king) and their point value.  To "lose material", for example, is to lose pieces or pawns, or trade pieces or pawns for something of a lower value. Example: "John traded his knight for a pawn. Because a knight is worth 3 points and a pawn is worth 1 point, John lost material in that trade".

• A superiority [or advantage (see "advantage")] in the total value of one's pieces and pawns. If you have more valuable pieces (for example, a queen against a knight and bishop) then you have a material advantage. Example: "Alice won a rook for a bishop. Since a rook is worth five points and a bishop is worth three points, Alice gained a material advantage.

Mating Attack

• An attack (see "attack") on the king, with the goal of giving checkmate.

• A situation where the king's escape squares are taken away, and checkmate (see "checkmate") is forced. Quiet, non-checking moves are often used to take away the king's escape squares.

• The phase of the game after the opening (see "opening") but before the endgame (see "endgame"). Usually, the middlegame starts when the players have brought out their pieces and are no longer following an opening line that they know. The middlegame is typically considered to end when there are very few pieces on the board, or when queens and some of the other pieces have been traded.

• A very short game. Most people say that a miniature has to be twenty-five moves or less.

• The exchange of bishop for knight. Most players consider the bishop a little better than the knight, but it depends on the position.

• A minor piece is a bishop or knight.

• A strategic plan in which a player advances a smaller number of pawns against a greater number of pawns on one wing (either the kingside or queenside). Usually the goal is to create weak squares or pawns in the opponent's position, and to open lines. A Minority Attack can be successful because, by definition, if you have two pawns versus three pawns then you also have an open file (see "file") to go along with your pawns.

• The ability of a piece or pieces to move around freely. For example, a knight in the center (see "center") typically has greater mobility (more available squares to which to move) than a knight on the side or edge of the board. Additionally, a player's entire position may have more mobility, if he/she has more space (see "space").  

• A single action on the chessboard. In chess, both players always take turns making moves. In chess notation, a move (move 1, 2, 3, etc) is considered complete when each side (white and black) has moved. Example: "The game between Amanda and Robert lasted for thirty moves; each player made thirty moves."

• Attacking (see "attack") two or more things at once. Usually this is caused by a fork or a discovered attack (see both "fork" and "discovered attack"). The multiple attack is one of the strongest methods of attack in chess, because the opponent will have trouble defending against more than one attack all at once.

 Mysterious Rook Move

• This phrase was made popular by Aron Nimzowitsch. This is a move by a rook to a file which is closed (see both "open file" and "closed file"). The player might be expecting the file to become open later, or trying to stop the opponent from opening the file.

Norm

• A level of performance in a tournament. Norms are required to earn certain titles. For example, to become a grandmaster, a player must make earn grandmaster norms in which he or she performs like a strong grandmaster in a very strong tournament.

• A system for writing down chess games. Algebraic notation is most common. It uses letters and numbers to describe the squares. There is also descriptive notation.

• A tournament which has no restrictions by age, rating, or gender. Anyone can compete.

• A file that has no pawns on it. An open file is a great place for rooks and queens, who may use the open file to invade the opponent's position.

• A game that begins with the moves 1.e4 e5. It may also be called a Double King's Pawn Opening.

• The beginning of a game, from the very first move until all the pieces are developed and the players begin creating middlegame plans.
• A way of starting the game which has been played before and is well-known. Most of the reasonable first moves fall into an opening. Example: "By responding to 1.e4 with 1...c5, I played the Sicilian Defense opening."

Open Position

• Open positions have few pawns in the center of the board. They tend to be tactical and favor long-range pieces like bishops.

• The openings that a player tends to play with white and black. For example, Bobby Fischer's opening repertoire consisted mostly of playing 1.e4 as white, meeting 1.e4 with the Sicilian Defense as black, and meeting 1.d4 with the King's Indian Defense.

Opponent

• In chess the "opponent" is the person you are playing against. For example, if you are white then the person sitting across the board playing the black pieces is your "opponent".

• When one player has a single bishop on the light squares and the other player has a single bishop on dark squares, we say the players have opposite-color bishops. Opposite-color bishops are often drawish in endgames since the players may blockade on the color their bishop control.

• A situation where the kings face each other with one square in between them, in a king-and-pawn ending. The side who is not to move has the opposition - because the opposing king has to step aside.

• This happens in a king-and-pawn ending, when after the opposition forces one side's king to move out of the way the other side's king then outflanks the opponent. This is the basic principle of winning the ending "king and pawn versus king", where the repeated outflanking allows the side with the pawn to gain control of the path to the queening square.

• An important square which cannot be controlled by the opponent and where one player hopes to establish a piece. Typically this is a central square, perhaps in the opponent's half of the board, where one player tries to place a knight, although outposts can also be used by other pieces.

• A passed pawn on the wing (rather than in the center) or, in general, distant from where the main battle is taking place. The advantage of an outside passed pawn is that it tends to distract the opponent's pieces from the main battle, since they must stop the pawn from queening.

• A strategy, devised by Aron Nimzowitsch, where a player protects strong points more times than is necessary. The idea is that by protecting the strong point, the pieces become more powerful.

Overworked Piece

• An overworked piece defends against multiple threats. Often an overworked piece can be exploited by executing one of the threats. If the overworked piece responds, it will leave the other threat undefended.

• A pawn which has no opposing pawns either on the file in front of it, or on the files next to it. A pawn which can advance to the queening square without having to worry about being captured or blocked by the opponent's pawns. The ultimate goal of a passed pawn is to reach the other side of the board (8th rank for white or 1st rank for black) and "promote" (see "promotion") to a better piece.

Passer

•  Short for passed pawn. See "passed pawn".

• Passive is the opposite of active. A passive piece or position has little mobility or chance to attack.

• An unkind term for a bad chess player.

Pattern

• An arrangement of chess pieces that is often repeated. Strong players know many tactical, checkmating, and positional patterns.

• Having several unblocked pawns in the center, usually side-by-side. Example: "White had pawns on e4 and d4, against Black's pawn on d6. So he had a pawn center." A pawn center usually gives good central control; however, sometimes a pawn center can be attacked if it is not well supported. 

• Several pawns on a diagonal, guarding each other. For example, pawns on f3, e4, and d5 form a pawn chain. Pawn chains have the advantage that the pawns guard each other; their disadvantage is that since they are all on one color they leave holes between them which are not guarded.

• A pawn or a group of pawns that is separated from the other pawns of the same color by an open file. An isolated pawn is a pawn island with only one pawn.

• An attacking method where one player advances a group of pawns toward the opponent, usually with the goal of destroying the opponent's king's pawn cover.

• The overall position of the players' pawns; since pawns cannot be moved very fast, the pawn structure often stays the same for a long time, determining what kind of plans the player's use.

• A situation where one player can check the opponent's king forever, but cannot checkmate it. Perpetual check is a draw if the side giving the checks wants it. When perpetual check happens, the players usually either agree to a draw or the same position is repeated three times, resulting in a draw by threefold repetition. See "threefold repetition".

• One unit on a chessboard. Usually when chess players say "piece", they mean a knight, bishop, queen, or rook. The kings and pawns are not considered "pieces". Example: "The chess teacher said that in the opening we should get our pieces into the game. We understood that this meant to bring out our knights, bishops, rooks, and queen; not to advance our king or push all of our pawns." 

• When a piece cannot move without exposing a more valuable piece (usually the king or queen) to attack. You can learn more in our chess term on pins in chess.

• A piece which cannot move because it is pinned; it must stay where it is to shield a more valuable piece from attack.

• A long-range piece (a rook, queen, or bishop) which is aimed at one of the opponent's valuable pieces,  with a less valuable defending piece blocking it.  The pinning piece is the attacking piece in a pin.

• The long-term purpose of a player's moves. A typical plan might be to create a pawn storm against the opponent's king (see "pawn-storm"), to create a weak square in an opponent's position, or to control an open file. A plan is different from calculation (see "calculation") in that planning involves looking far ahead, but without seeing the exact moves.    

• A poisoned pawn can be captured, but capturing it will cause problems. An example is a wing pawn that that may be captured by the queen at the cost of time and development.

• The arrangement of each side’s pieces and pawns on the board. 

•  "Positional" means the long-term strengths and weaknesses in a player's position. "Positional play" means play that is based around strengthening one's position, or weakening one's opponent's. A "positional player" focuses on building up long-term advantages. Positional is the opposite of "tactical", which is concerned with immediate and temporary things that are happening on the board (see "tactics").

• Literally meaning "after death"; in chess it means a discussion between the two opponents after a game. The players may explore different ways they could have played, or discuss why they made the moves that they did. Example: "In the post-mortem, we discovered that I could have won a rook by a knight fork. Neither of us saw it during the game!"

• The act of turning a pawn into another piece (queen, rook, bishop, or knight) after it reaches the other side of the board. See also "underpromotion". 

Prophylaxis

• Prophylaxis (or a prophylactic move) tries to prevent the opponent's ideas.

Protected

• A protected piece or pawn is defended by another piece.

Protected Passed Pawn

• The term "protected passed pawn" refers to a passed pawn (see "passed pawn") that is guarded (protected) by another pawn. If a passed pawn is protected by a piece (like a rook) it is not referred to as a protected passed pawn. Only a passed pawn that is protected by another pawn is referred to as a 'protected passed pawn'.

• The act of promoting (see "promotion") a pawn to a new queen after the pawn reaches the far side of the board.

• The side of the board where the queen starts out. For White, this is the left-hand side; for Black, it is the right-hand side. The queenside includes the a-, b-, c-, and d-files. "Castling queenside" means to castle on the side of the board where the queen started; to "castle long".

• A move that is not a check, capture, or direct threat.

• A horizontal (side-to-side) line on the chessboard. In notation, ranks are the numbered lines; for example, third rank, fourth rank, etc.

• Chess played with a fast time control (see "time control"). A game is usually considered "rapid" if a player has between 10 and 60 minutes for all the moves.

• A way that chess federations measure a player's skill by a number. The main rating system was created by Arpad Elo, and is known as the Elo rating system. If a player wins, his or her rating goes up; if he or she loses, it goes down. How much it goes up or down depends on the rating of the opponent.

Recapture

• (See "capture"). A recapture is made when our opponent (see "opponent") has captured one of our pieces, and we capture his or her piece on that same square. Example: Sally's opponent captured her pawn on c6, but Sally recaptured with the pawn on b7. (I'm personally inclined to omit the example. I don't think it's essential.)

Refute

• To show that a move, plan, combination, or opening variation is wrong.

• A pin which is not absolute (see "absolute pin"). The pinned piece can legally move, but moving it would lose a more valuable piece. For example, a knight that is pinned to the queen is in a relative pin; according the the rules it can move, but moving it would lose the queen. (See "pin").

Resign

• To give up and admit defeat in a chess game. Resigning a game has exactly the same result as being checkmated - either way it is a loss. Players often resign to avoid wasting time playing a game that they know they are going to lose.

• Having to do with a past time in history when less was known about chess, and players played "by the light of nature", attacking (see "attack") and sacrificing (see "sacrifice") without worrying too much if their ideas were correct. Sometimes people talk about a modern chess player's style as being "romantic" - or they might call a certain game or move "romantic", if it involves sacrificing pieces and playing carelessly and creatively.

• A maneuver which activates a rook by moving it up and to the side, in front of its own pawns. Usually, a rook is lifted on the third or fourth rank. This is an alternative to activating a rook by moving it to an open file.

• A tournament where everybody plays against everybody. Usually this is a smaller (in the number of players) but more important tournament. In a round-robin the order that the players play each other is usually random, but since every player plays against every other player, it is considered to be a very fair method.

• A fork between the king and queen. See "fork".

• Short for "sacrifice". See "sacrifice".

• The act of giving up material (either making a trade that loses points or simply losing a piece or pawn for nothing) with the goal of getting something else in return. For example, a player may sacrifice the queen in order to open up a square for a knight where it can checkmate the opponent. A player may also make more strategic sacrifices, such as sacrificing a pawn to gain time to develop, or sacrificing a piece to destroy the opponent's king's pawn cover. 

• Scholar's mate is also called the "four-move checkmate." In Scholar's Mate, White tries to play 1.e4, 2.Bc4, 3.Qh5 (or Qf3), and 4.Qxf7 mate.

• A piece of paper on which the players record the game. The scoresheet has a column for White’s moves and a column for Black’s moves. The players must write down both their moves and their opponent’s moves using chess notation. See "notation".

• A rare tactic in which a repeated discovered check allows one piece to go on a rampage, capturing multiple enemy pieces. See also "windmill". The most famous example of a see-saw happened in the game Torre-Lasker, Moscow 1925.

• A game beginning with the move 1.e4, followed by any move other than 1...e5. For example, a Sicilian defense (1.e4 c5), French defense (1.e4 e6), Caro-Kann defense (1.e4 c6) or others. See also "open game" and "closed game".
• A position which is somewhat open (having many open files and diagonals, and few blocked pawn) and somewhat closed (having blocked pawns and few open lines).

• In chess, a sharp position is one where the slightest mistake can change the result of the game.

• A strong, unexpected move which totally changes the course of the game.

Sideline

• A "sideline" is the opposite of the "main line" (see "main line"). The term sideline or sidelines is often used to describe opening variations (see "opening" and "variation"). Example: "Billy played the sideline, which is not what I was expecting as I had spent most of my time learning the main line of this opening."

Simplify

• To exchange pieces and make the position more "simple". Sometimes players simplify the position in order to win more easily with extra material (it is easier to win with extra material when there are less pieces on the board overall), to defend against the opponent's attack, or to use a long-term advantage.

• Short for "simultaneous exhibition". See "simultaneous exhibition".

• A type of event or show ("exhibition") where a player plays many opponents at one time. Usually his or her opponents are sitting in a circle, each with their own board, and the player giving the simultaneous exhibition walks from board to board, making moves on each. Usually the player giving the simultaneous exhibition is a master and the opponents are weaker players. See also "simul".

Skewer

• A move which threatens a valuable piece (such as the king or queen), forcing that piece to move away and allowing the attacking piece to take a less valuable piece behind the valuable one. Imagine a bishop checking a king, forcing the king to move away and allowing the bishop to take a queen which was behind the king. A skewer is the opposite of a pin, since in the skewer the more valuable piece is in front. See "pin". You can learn more in our dedicated chess term on skewers in chess.

• Games played for fun or otherwise not part of a tournament; casual games. Usually during tournaments there is a "skittles room", where players can go and play blitz games for fun (see "blitz chess"), analyze their tournament games (see "post-mortem"), or just talk without distracting the players in the tournament.

• A checkmate by a knight against a king which has no way out because all of its escape squares are blocked by its own pieces. The king's own pieces keep it from moving, while the enemy knight puts it in check. It is called "smothered" because the king is squeezed in by its own pieces and cannot breathe.

• A move or plan is sound if it cannot be defeated even if your opponent play the best moves. An attack that is sound is one that, even if the defender defends perfectly, will still give the attacker a good position.

• Space is the squares a player controls. A player with more space, called a space advantage, controls more squares.

• One final check given by a player who is losing, which only delays his/her loss for one move, while the opponent gets out of check.

• Stalemate occurs when a player has no legal moves but is not in check. A stalemate is a draw.

• A strategy is a plan. Strategy usually means that you are thinking long-term, rather than "I go here, he goes there" type of thinking. It means looking far ahead but without seeing the exact moves or positions that you will reach. 

• A study In chess is a made-up position. A composer invents a study to show a beautiful, deep, or instructive idea.

•  The way a player tends to play, or the positions he/she likes best. A player's style might be aggressive, tactical, strategic, positional, or others. Example: "Mikhail Tal had a very aggressive, attacking style - he liked open positions where he had a chance to attack his opponent's king. Tigran Petrosian had a very defensive, positional style - he liked to try to create strategic weaknesses in his opponent's position."

• A time control where a player must finish the game before his/her clock runs out. For example, a sudden death time control might be "Game in 60", which means that each player must not use more than sixty minutes for the game, or he/she will lose on time.

• A trick that allows a player who has a bad position to turn the game around. A swindle can only happen if the player with the advantage makes a mistake. Example: "I was losing my third round game, but then I managed to swindle my opponent and win. He fell for my trick because he didn't see the best move."

• A system for deciding who plays against whom in chess tournaments that are too big for everybody to play everybody (a tournament where everyone plays everyone is a Round Robin. See "Round Robin"). The Swiss system is usually used in big, open tournaments. The system works by having players with the same number of points play against each other, with the top half (by ELO rating. See "ELO Rating") in each score group playing the bottom half.

Symbols (Notation Symbols)

• Symbols are used in notation (see "notation") to explain whether a move is good or bad, and whether a position is better for white, better for black, or equal. Some symbols include "!" after a move, which means that the move played was a good move. Sometimes you will even see "!!" which means that a move played was a great move, maybe even brilliant. After a move or position is reached, you will also see the "=" symbol, which means that the position is considered to be equal. You may also see a "+/-" symbol which means the position is better for white. 

• There is symmetry in a position when both players' pieces are arranged in exactly the same way. If the board were folded in half at the middle, each piece would land on the same kind of opposing piece. For example, a white rook would land on a black rook, a white bishop would land on a black bishop, etc. At the beginning of a game, the position is symmetrical. There can also be symmetry just in pawn structure, when each side's pawns look exactly the same, but the pieces might be placed differently.

Tactic(s)

• Short term attacks, such as forks, pins, skewers, and other kinds of attacks that take place over a few moves. The opposite of long-term strategy. Example: "If you want to be a great chess player, you need to be good at both tactics and planning. What good is it to plan to win a weak pawn twenty moves from now, if you let your opponent fork your king and rook in an immediate tactic?!" 

• A tactician is a style of player who is very good at - or likes - tactics. A player who is good at finding forks, pins, and other small attacks, as opposed to long-term strategy. Example: "Alekhine was a good tactician - you had to be very careful or you might lose a piece against him to some kind of fork or you could be cleverly checkmated!"

•  A single move which improves your position. For example, you "gain a tempo" if you get the chance to develop a piece while your opponent uses the time to do nothing useful. You can also "gain a tempo" if you are able to make a useful or developing move while creating a threat that forces your opponent to defend with an otherwise useless move.

• Moves or positions which have been played or studied before. Theory is what the human race believes to be correct about chess - for example, opening theory includes the starting moves and variations which have been played before and what people generally think about them. There is also endgame theory, which includes positions which are known and considered to be won, lost, or drawn. Example: "According to endgame theory, king and queen should win against king and rook."

• A move which one side plans to make, which would be bad for the opponent. Example: "If it were my move, I could checkmate my opponent. So I had a threat of checkmate. It was his move, so he had to defend against my threat, or he would lose." Threats can be as big as a threat to checkmate or a threat to the opponent's queen, or as small as a threat to weaken his/her pawn structure. 

• When the same position is reached three times in a game, the players may claim a draw by three-fold repetition.

• Tiebreaks are used to decide who wins a prize that cannot be divided (such as a trophy or a title) if multiple players get the same score. Tiebreaks might be based on the opponents' average ratings, the opponents' total scores, the number of games you won, or the number of games in which you had black.

• The amount of time that the players have to finish a game. A chess clock is used to keep track of the time (see "clock").  A common time control for scholastic tournaments is "game in thirty minutes". This means that each player has thirty minutes to play all of his/her moves; if more than thirty minutes is used, he/she will lose the game. Blitz chess uses a time control of five minutes per game (see "blitz chess"). Also, there is the classical time control, "forty moves in two hours, and sudden death in an hour."

• Some electronic clocks (see "clock") allow the players to use a time delay. This means that the clock waits - usually - five seconds before it starts counting off time. If a player uses less than five seconds for a move, no time is subtracted from his/her clock. This means that if a position is very easy, such as king and queen versus king, a player will not lose on time by simply not being able to play the moves fast enough.

• Time pressure, or time trouble, happens when a player has very little time to play his or her moves. This means that the player cannot think for a long time and it often leads to mistakes. It usually happens if a player used too much time (see "clock") earlier in the game, and not much time is left in the time control. See "time control".

• A rule, which is used in all serious chess, that if a player touches a piece, he/she has to move that piece. If a player touches one of the opponent's pieces, that player has to capture (see "capture") the piece if it is possible.

• A chess competition, where many players compete against each other. A tournament has at least three players; if it has only two then that is called a "match" (see "match").

Tournament Director

• A tournament director is the person who helps chess players with the rules and restrictions that are required during a chess tournament. Every chess tournament --whether online or "over the board"-- has guidelines and rules that chess players need to learn, know and follow. The tournament director (see also "arbiter") knows all of these rules, and therefore helps with this process. In a tournament, for example, all players must move a piece or capture an opponent's piece if they touch it. A tournament director or an arbiter will help to enforce these rules.

Trade

• A trade is an exchange (see "exchange") of pieces. Most trades happen when one player captures an opponent's (see "opponent") piece of the same value as the capturing piece and the opponent recaptures.

Transpose/Transposition

• A transposition in chess occurs when, through a series of moves, a position is reached that is more commonly seen through a different series of moves. However, it is nonetheless the same exact position that is on the chess board, even though the moves were different. Example: "Tom noticed that the position had transposed into a the same position that he more commonly sees reached by a different move order." 

Trap

• A trap is a plan for your opponent to miss something important and therefore blunder (see "blunder"). Usually, the term trap is used when either you or your opponent are trying for a tactical (see "tactic") trick of some kind. This is trick is not usually forced (see "forced") when we use the term trap. 

Triangulation

• Triangulation is a very advanced way of "out-maneuvering" the enemy king with your own king in order to gain the opposition (see "opposition"). Usually this involves the creation of an imaginary triangle, if one were to draw lines between the three squares used in this maneuver (see "maneuver")

• A position where it is too complicated to tell who has the advantage (see "advantage"). Example: "I couldn't tell if White stood better, if Black stood better, or if the position was equal! All I knew was that it was very complicated. So I wrote that it was an unclear position."

• To remove an important defensive piece, with the goal of attacking what it was guarding. Usually undermining has to do with pawn chains (see "pawn chains"); undermining a pawn chain means to attack the base pawn (see "base pawn"), trying to knock it out so you can destroy the whole chain.

• Promoting (see "promotion") a pawn to a piece less than a queen (in other words, promoting a pawn to a knight, rook, or bishop). Since the queen is the strongest piece, players almost always choose to promote their pawns to queens. But sometimes underpromotion occurs when there are special reasons that a player needs a weaker piece rather than a queen.

• Unusual play; moves or style that is different than the way most people play, or different from the ways of playing which are generally considered to be correct.

• To break or escape from a pin (see "pin"). A player may unpin by: 1) moving the valuable piece away, thus allowing the pinned piece to move freely; 2) putting a less valuable piece in between the valuable piece and the pinned piece; 3) blocking the pin by putting a less valuable piece in front of the pinned piece; or 4) chasing away the pinning piece.

USCF

• The United States Chess Federation is the organization that officially takes care of chess in the United States. People used to call it the USCF (and many people still do), but their official name now is US Chess Federation.

• To vacate is to leave a place; in chess, vacating means to clear one of your own pieces out of the way so another one of your pieces can use that square or file (see "file"). There can be vacating sacrifices, where you intentionally lose one of your own pieces to make way for a different one.

• A variation is one way a game could go, or could have gone; it is a series of moves by White and Black that are forced or logical. A variation may be a series of moves that a player thinks about, but if he/she decides not to play the first move of the variation, it will not happen in the game.
• A variation is also one possible way of playing within a larger opening. For example, the "Averbakh variation of the King's Indian Defense", is a reference to a possible variation of a bigger Opening [the King's Indian Defense is an Opening (see "Opening")].

Visualize

• To "visualize" is to try and see a position or a series of moves "in your head" without actually moving the pieces on the chess board.

• A move that doesn't change the position. A waiting move is often played to pass the move to the opponent.

• A pawn that cannot be easily guarded, especially a pawn that cannot be guarded by another pawn, such as an isolated pawn (see "isolated pawn"), doubled pawn see "doubled pawn", or backward pawn (see "backward pawn").

• A square which is strategically (see "strategy") important (it is usually in an important area of the board, such as in the center or in the opponent's side of the board) and cannot be easily guarded. A weak square usually cannot be easily guarded by one side's pawns, and can often become an outpost (see "outpost") for the other side. Also known as a "hole".

• A square, group of squares, or piece that is difficult to defend, such as a doubled pawn, isolated pawn, backward pawn, or hole.

• A rare tactic in which a repeated discovered check allows one piece to go on a rampage, capturing multiple enemy pieces. (See also "see-saw"). The most famous example of a windmill happened in the game Torre-Lasker, Moscow 1925.

• The sides of the board, as opposed to the center. Generally, these are the a-, b-, g-, and h-files. 

• A position where a player should win the game, if both players play the best moves. For example, if you are up a queen you might have a winning position. A winning position is not the same as a win; frequently you hear players say such things as "I had a winning position but made a terrible mistake and lost".

• An "x-ray" is a machine which sees through things. An x-ray in chess is when one of your long-range pieces (a rook, bishop, or queen) acts "through" your opponents piece to attack (see "attack") or defend (see "defend") beyond it.

• A German word meaning “move-need.” Zugzwang occurs when every legal move worsens the position, but not moving (if that were legal) would keep a good position. 

• A German word meaning "in-between check". This is a check that is inserted -- in between -- a forcing sequence of moves, which changes the result of the sequence. See also "zwischenzug".

• A German word meaning "in-between move". An - often unexpected - move inserted in a forcing sequence of moves, which changes the result of the sequence. See also "zwischenschach".