Backgammon 

Backgammon is a game for two players, played on a board consisting of twenty-four narrow triangles called points. The triangles alternate in color and are grouped into four quadrants of six triangles each. The quadrants are referred to as a player’s home board and outer board, and the opponent’s home board and outer board. The home and outer boards are separated from each other by a ridge down the center of the board called the bar.

Figure 1.  A board with the checkers in their initial position.
An alternate arrangement is the reverse of the one shown here, with the home board on the left and the outer board on the right.

The points are numbered for either player starting in that player’s home board. The outermost point is the twenty-four point, which is also the opponent’s one point. Each player has fifteen checkers of their own color. The initial arrangement of checkers is: two on each player’s twenty-four point, five on each player’s thirteen point, three on each player’s eight point, and five on each player’s six point.

Both players have their own pair of dice and a dice cup used for shaking. A doubling cube, with the numerals 2, 4, 8, 16, 32, and 64 on its faces, is used to keep track of the current stake of the game.

Explore more resources for new players. See our New to Backgammon collection of articles.

Object of the Game

The object of the game is to move all your checkers into your own home board and then bear them off. The first player to bear off all of their checkers wins the game

Figure 2.  Direction of movement of White’s checkers. Red’s checkers move in the opposite direction.

During the course of the game, a player who feels they have a sufficient advantage may propose doubling the stakes.

Movement of the Checkers

To start the game, each player throws a single die. This determines both the player to go first and the numbers to be played. If equal numbers come up, then both players roll again until they roll different numbers. The player throwing the higher number now moves their checkers according to the numbers showing on both dice. After the first roll, the players throw two dice and alternate turns.The roll of the dice indicates how many points, or pips, the player is to move their checkers. The checkers are always moved forward, to a lower-numbered point. The following rules apply:

1. A checker may be moved only to an open point, one that is not occupied by two or more opposing checkers. 
2. The numbers on the two dice constitute separate moves. For example, if a player rolls 5 and 3, they may move one checker five spaces to an open point and another checker three spaces to an open point, or they may move the one checker a total of eight spaces to an open point, but only if the intermediate point (either three or five spaces from the starting point) is also open.

Figure 3.  Two ways that White can play a roll of    .

1. A player who rolls doubles plays the numbers shown on the dice twice. A roll of 6 and 6 means that the player has four sixes to use, and they may move any combination of checkers they feel appropriate to complete this requirement. 
2. A player must use both numbers of a roll if this is legally possible (or all four numbers of a double). When only one number can be played, the player must play that number. Or if either number can be played but not both, the player must play the larger one. When neither number can be used, the player loses their turn. In the case of doubles, when all four numbers cannot be played, the player must play as many numbers as they can.

The object of the game is to move all your checkers into your own home board and then bear them off. The first player to bear off all of their checkers wins the game

Hitting and Entering

A point occupied by a single checker of either color is called a blot. If an opposing checker lands on a blot, the blot is hit and placed on the bar.Any time a player has one or more checkers on the bar, their first obligation is to enter those checker(s) into the opposing home board. A checker is entered by moving it to an open point corresponding to one of the numbers on the rolled dice. For example, if a player rolls 4 and 6, they may enter a checker onto either the opponent’s four point or six point, so long as the prospective point is not occupied by two or more of the opponent’s checkers.

Figure 4.  If White rolls   with a checker on the bar, they must enter the checker onto Red’s four point since Red’s six point is not open.

If neither of the points is open, the player loses their turn. If a player is able to enter some but not all of their checkers, they must enter as many as they can and then forfeit the remainder of their turn. After the last of a player’s checkers has been entered, any unused numbers on the dice must be played, by moving either the checker that was entered or a different checker.

Bearing Off

Once a player has moved all of their fifteen checkers into their home board, they may commence bearing off. A player bears off a checker by rolling a number that corresponds to the point on which the checker resides, and then removing that checker from the board. Thus, rolling a 6 permits the player to remove a checker from the six point. If there is no checker on the point indicated by the roll, the player must make a legal move using a checker on a higher-numbered point. If there are no checkers on higher-numbered points, the player is permitted (and required) to remove a checker from the highest point on which one of thier checkers resides. A player is under no obligation to bear off if they can make an otherwise legal move.

Figure 5.  White rolls
  and bears off two checkers.

A player must have all of their active checkers in their home board in order to bear off. If a checker is hit during the bear-off process, the player must bring that checker back to their home board before continuing to bear off. The first player to bear off all fifteen checkers wins the game

Doubling

Backgammon is played for an agreed stake per point. Each game starts at one point. During the course of the game, a player who feels they have a sufficient advantage may propose doubling the stakes. They may do this only at the start of thier own turn and before they have rolled the dice. A player who is offered a double may refuse, in which case they concede the game and pays one point. Otherwise, they must accept the double and play on for the new higher stakes. A player who accepts a double becomes the owner of the cube and only they may make the next double. Subsequent doubles in the same game are called redoubles. If a player refuses a redouble, they must pay the number of points that were at stake prior to the redouble. Otherwise, they become the new owner of the cube and the game continues at twice the previous stakes. There is no limit to the number of redoubles in a game.

Gammons and Backgammons

At the end of the game, if the losing player has borne off at least one checker, they lose only the value showing on the doubling cube (one point, if there have been no doubles). However, if the loser has not borne off any of their checkers, they are gammoned and lose twice the value of the doubling cube. Or, worse, if the loser has not borne off any of their checkers and still has a checker on the bar or in the winner’s home board, they are backgammoned and lose three times the value of the doubling cube.

Optional Rules

The following optional rules are in widespread use.

1. Automatic doubles. If identical numbers are thrown on the first roll, the stakes are doubled. The doubling cube is turned to 2 and remains in the middle. Players usually agree to limit the number of automatic doubles to one per game. 
2. Beavers. When a player is doubled, they may immediately redouble (beaver) while retaining possession of the cube. The original doubler has the option of accepting or refusing as with a normal double. 
3. The Jacoby Rule. Gammons and backgammons count only as a single game if neither player has offered a double during the course of the game. This rule speeds up play by eliminating situations where a player avoids doubling so they can play on for a gammon.

Irregularities

1. The dice must be rolled together and land flat on the surface of the right-hand section of the board. The player must reroll both dice if a die lands outside the right-hand board, or lands on a checker, or does not land flat. 
2. A turn is completed when the player picks up their dice. If the play is incomplete or otherwise illegal, the opponent has the option of accepting the play as made or of requiring the player to make a legal play. A play is deemed to have been accepted as made when the opponent rolls their dice or offers a double to start their own turn. 
3. If a player rolls before their opponent has completed their turn by picking up the dice, the player’s roll is voided. This rule is generally waived any time a play is forced or when there is no further contact between the opposing forces.

Common Questions

Q: Who goes first?

To decide who goes first, you and your opponent each roll one die. In the case of a tie, you both roll again. The player who rolls the higher number goes first. That player does not roll the dice again; they play the two numbers just rolled on their first turn.

Notice that the player who goes first never has doubles on their first turn because ties on the first roll are always broken.

Q: What is the object of the game?

The object in backgammon is to move all of your checkers around the board into your home board and then bear them off. The first player to get all their checkers off the board is the winner.

Q: What is the ace-point?

The ace-point is another name for the one-point, the last point you can move your checkers to before bearing them off. Your two farthest back checkers start on the opponent’s ace-point.

 Q: Can I pass when it’s my turn?

No, you must play your roll if there is any legal way to do so. If you can’t play all of your numbers, you must play as many as you can. So if you roll    and can only play three of your four 6’s, that’s what you must do.

 Q: Is hit-and-run allowed (also known as “pick and pass”)?

Yes, if you hit a checker, you are allowed to run your hitter to safety. Here is an example:

White rolls 5-2:  White may hit Red’s checker on the five-point and then move their hitter to safety on the three-point.

Q: What is a doubling cube?

A doubling cube is a cubical block, a little larger than a regular die, with the numbers 2, 4, 8, 16, 32, and 64 printed on its faces. It is sometimes simply called the cube. The purpose is to allow players to bet on the game as they are playing. 

Q: How do you use a doubling cube?

At the beginning of the game, the doubling cube is placed halfway between the players, either on the bar or at the side of the board, with the number 64 face up. The 64 means that the stakes have not been doubled yet. (Most doubling cubes do not have a 1, so the number 64 is understood to represent 1)  The position of the cube, halfway between the players, indicates that both players have access to it. That is, either player can make the first double.

At any point during the game, a player who thinks they have a sufficient advantage may double the stakes. They can do this only at the beginning of their turn, before they have rolled the dice.

When a double is offered, the opponent may refuse the double, in which case they resign the game and forfeit the current stakes. The current stake is the value of the cube before the double is offered, in this case one point.

If the opponent doesn’t want to resign, they may accept the double, and agree to continue play at double the previous stakes. They place the cube on their side of the board with the number 2 face up. The number 2 represents the fact that the stakes are now doubled. The position of the cube means that player now owns the doubling cube and only they may make the next double.

If the game later turns around and the player who owns the cube feels they now have an advantage, they may redouble the stakes to 4. Their opponent may refuse and give up the current stakes (now two units) or they may accept and continue play at quadruple the initial stakes.

There is no limit to the number of doubles and redoubles in a single game, except that no player may double twice in a row.

At the end of the game, the loser pays the winner the value of the doubling cube in whatever units they have agreed to play for. For example, if playing for one dollar a point and the doubling cube shows 4, then the loser pays the winner four dollars. In the case of a gammon or backgammon, this amount is doubled or tripled.

Yes, you can double at the start of any turn. You have to be alert, though; your opponent, seeing that you can’t move, may roll their dice without waiting to see what you do. Just ask them to “wait, please” as they pick up their dice while you decide whether or not to double.

Some people play that if the two players roll the same number on the first roll of the game, then the doubling cube is automatically turned to 2. The cube stays in the middle but now the first voluntary double of the game will be offered at 4. If the players roll the same number again, then the cube is turned up another notch, though players often agree to limit the number of automatic doubles to one per game.

Q: What is match play?

When backgammon tournaments are held to determine an overall winner, the usual style of competition is match play. Competitors are paired off, and each pair plays a series of games to decide which player progresses to the next round of the tournament. This series of games is called a match. Match play is also popular on backgammon play sites.Matches are played to a specified number of points. The first player to accumulate the required points wins the match. Points are awarded in the usual manner: 1 for a single game, 2 for a gammon, and 3 for a backgammon. The doubling cube is used, so the winner of each game receives the value of the game multiplied by the final value of the cube. Automatic doubles, beavers, and the Jacoby rule are not used in match play.

Q: What is the Crawford rule?

If you are playing a match up to n points and one player reaches n – 1 points, the Crawford rule says that the doubling cube is out of play for one game. This one game without doubling is called the Crawford game. After the Crawford game, the doubling cube is back in play again. The Crawford rule is a standard part of match play.

Match to 5 |  | White Score | Black Score |
Game 1: | White wins 2 points | 2 | 0 | Doubling Allowed
Game 2: | Black wins 1 point | 2 | 1 | Doubling Allowed
Game 3: | White wins 2 points | 4 | 1 | Doubling Allowed
Game 4: | Black wins 1 point | 4 | 2 | Crawford Game
Game 5: | Black wins 2 points | 4 | 4 | Doubling Allowed
Game 6: | White wins 2 points | 6 | 4 | Doubling Allowed

In this example, White and Black are playing a 5-point match. After three games, White has 4 points, one short of what they need for the match. That triggers the Crawford rule, and no doubling is allowed in the next game, Game 4.

The idea behind the rule is that without restrictions on doubling, the player who is behind in the match would double at their first opportunity every game. This reduces the number of games needed to win the match, lessening the value of the points held by the player who is winning. On the other hand, if the cube were taken out of play completely, the player who is behind in the match would have to win all their remaining points without any help from the doubling cube at all. The Crawford rule is an intelligent compromise. The Crawford rule was devised by John R. Crawford, co-author of The Backgammon Book.

CHESS

Initial setup

Chess is played on a chessboard, a square board divided into a grid of 64 squares (eight-by-eight) of alternating color (similar to the board used in draughts). Regardless of the actual colors of the board, the lighter-colored squares are called "light" or "white", and the darker-colored squares are called "dark" or "black". Sixteen "white" and sixteen "black" pieces are placed on the board at the beginning of the game. The board is placed so that a white square is in each player's near-right corner. Horizontal rows are called ranks, and vertical columns are called files.

At the beginning of the game, the pieces are arranged as shown in the diagram: for each side one king, one queen, two rooks, two bishops, two knights, and eight pawns. The pieces are placed, one per square, as follows:

• Rooks are placed on the outside corners, right and left edge.
• Knights are placed immediately inside of the rooks.
• Bishops are placed immediately inside of the knights.
• The queen is placed on the central square of the same color of that of the piece: white queen on the white square and black queen on the black square.
• The king takes the vacant spot next to the queen.
• Pawns are placed one square in front of all of the other pieces.

Popular mnemonics used to remember the setup are "queen on her own color" and "white on right". The latter refers to setting up the board so that the square closest to each player's right is white.
  

Gameplay 

The player controlling the white pieces is named "White"; the player controlling the black pieces is named "Black". White moves first, then players alternate moves. Making a move is required; it is not legal to skip a move, even when having to move is detrimental. Play continues until a king is checkmated, a player resigns, or a draw is declared, as explained below. 

The official chess rules do not include a procedure for determining who plays White. This decision is made by mutual agreement, in which case some kind of random choice such as flipping a coin can be employed. A common method is for one player to conceal a pawn of each color in either hand; the other player chooses a hand to open and receives the color of the piece that is revealed.

Movement

Basic moves 

Each type of chess piece has its own method of movement. A piece moves to a vacant square except when capturing an opponent's piece.

Except for any move of the knight and castling, pieces cannot jump over other pieces. A piece is captured (or taken) when an attacking enemy piece replaces it on its square. The captured piece is thereby permanently removed from the game. The king can be put in check but cannot be captured (see below).

• The king moves exactly one square horizontally, vertically, or diagonally. A special move with the king known as castling is allowed only once per player, per game (see below).
• A rook moves any number of vacant squares horizontally or vertically. It also is moved when castling.
• A bishop moves any number of vacant squares diagonally. (Thus a bishop can move to only light or dark squares, not both.)
• The queen moves any number of vacant squares horizontally, vertically, or diagonally.
• A knight moves to one of the nearest squares not on the same rank, file, or diagonal. (This can be thought of as moving two squares horizontally then one square vertically, or moving one square horizontally then two squares vertically—i.e. in an "L" pattern.) The knight is not blocked by other pieces; it jumps to the new location.
• Pawns have the most complex rules of movement:
• A pawn moves straight forward one square, if that square is vacant. If it has not yet moved, a pawn also has the option of moving two squares straight forward, provided both squares are vacant. Pawns cannot move backwards.
• A pawn, unlike other pieces, captures differently from how it moves. A pawn can capture an enemy piece on either of the two squares diagonally in front of the pawn. It cannot move to those squares when vacant except when capturing en passant.

The pawn is also involved in the two special moves en passant and promotion.
 

Castling 

Castling consists of moving the king two squares towards a rook, then placing the rook on the other side of the king, adjacent to it. Castling is only permissible if all of the following conditions hold:[11]

• The king and rook involved in castling must not have previously moved;
• There must be no pieces between the king and the rook;
• The king may not currently be under attack, nor may the king pass through or end up in a square that is under attack by an enemy piece (though the rook is permitted to be under attack and to pass over an attacked square);
• The castling must be kingside or queenside as shown in the diagram 

 
 En passant
When a pawn advances two squares on its initial move and ends the turn adjacent to an enemy pawn on the same rank, it may be captured en passant by the enemy pawn as if it had moved only one square. This capture is legal only on the move immediately following the pawn's advance. The diagrams demonstrate an instance of this: if the white pawn moves from a2 to a4, the black pawn on b4 can capture it en passant, moving from b4 to a3, and the white pawn on a4 is removed from the board.

Promotion

If a player advances a pawn to its eighth rank, the pawn is then promoted (converted) to a queen, rook, bishop, or knight of the same color at the choice of the player (a queen is usually chosen). The choice is not limited to previously captured pieces. Hence it is theoretically possible for a player to have up to nine queens or up to ten rooks, bishops, or knights if all of the player's pawns are promoted.
 

Check 

A king is in check when it is under attack by at least one enemy piece. A piece unable to move because it would place its own king in check (it is pinned against its own king) may still deliver check to the opposing player.

It is illegal to make a move that places or leaves one's king in check. The possible ways to get out of check are:

• Move the king to a square where it is not in check.
• Capture the checking piece.
• Interpose a piece between the king and the opponent's threatening piece (block the check).

In informal games, it is customary to announce "check" when making a move that puts the opponent's king in check. In formal competitions, however, check is rarely announced.
 

End of the game

Checkmate 

If a player's king is placed in check and there is no legal move that player can make to escape check, then the king is said to be checkmated, the game ends, and that player loses.[22] Unlike the other pieces, the king is never captured.[23]

The diagram shows an example checkmate position. The white king is threatened by the black queen; the empty square to which the king could move is also threatened; and the king cannot capture the queen, because it would then be in check by the rook. 

Resigning

Either player may resign at any time, conceding the game to the opponent. To indicate resignation, the player may say "I resign". Tipping over the king also indicates resignation, but it should be distinguished from accidentally knocking the king over. Stopping both clocks is not an indication of resigning, since clocks can be stopped to call the arbiter. An offer of a handshake is sometimes used, but it could be mistaken for a draw offer.

Under FIDE Laws, a resignation by one player results in a draw if their opponent has no way to checkmate them via any series of legal moves, or a loss by that player otherwise.

 Draws 

The game ends in a draw if any of these conditions occur:

• The player to move is not in check and has no legal move. This situation is called a stalemate. An example of such a position is shown in the adjacent diagram.
• The game reaches a dead position.
• Both players agree to a draw after one of the players makes such an offer.

In addition, in the FIDE rules, if a player has run out of time (see below), or has resigned, but the position is such that there is no way for the opponent to give checkmate by any series of legal moves, the game is a draw.

FIDE's competitive rules of play allow a player to claim a draw in either of two situations:

• Fifty moves have been made by each player without a capture or promotion of a pawn (this is the fifty-move rule);
• The same position has appeared three times (or has appeared twice and the player claiming the draw can force the third appearance); this is the threefold repetition rule.

These rules help prevent games from being extended indefinitely in tournaments.

There is no longer a rule specifically defining perpetual check as a draw. In such a situation, either the threefold repetition rule or the fifty-move rule will eventually come into effect. More often, the players will simply agree to a draw.

Dead position 

A dead position is defined as a position where neither player can checkmate their opponent's king by any sequence of legal moves. According to the rules of chess the game is immediately terminated the moment a dead position appears on the board.

Some basic endings are always dead positions; for example:

• king against king;
• king against king and bishop;
• king against king and knight.

Blocked positions can arise in which progress is impossible for either side, such as the diagrammed position;[33] these too are dead positions.

USCF rules, for games played under a time control that does not include delay or increment, allow draw claims for "insufficient losing chances". For example, if each player has only a king and a knight, checkmate is only achievable with the co-operation of both players, even if it is not a dead position.

Touch-move rule

The touch-move rule is a fundamental principle in chess, ensuring that players commit to moves deliberated mentally, without physically experimenting on the board. According to this rule, a player who touches a piece with the intention of moving it must then move it if legally possible. This rule also applies to capturing: a player who touches an opponent's piece must capture it if a legal capture is available. Special considerations apply for castling and pawn promotion, reflecting their unique nature in the game.

A player who touches a piece to adjust its physical position within a square must first alert the opponent by saying J'adoube or "I adjust". Once the game has started, only the player with the move may touch the pieces on the board.