Free Skill Game - Chess Challenge at SkillArcade

Game Goals

Place your opponent's king in checkmate.

Game Rules

Chess Challenge includes three variations of chess, which you can choose while negotiating with a potential opponent. These are Traditional Chess, Fischer Random Chess, and Red Square Chess. If you are already familiar with the rules of chess, you can skip the next section, and proceed to the rules for the other two variations.

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Traditional Chess

Each player has 16 pieces, one of which is a king. Players take turns moving their pieces. The intermediate goal is to advance your pieces into strategic positions, and to capture your opponent's pieces. The ultimate goal is to "checkmate" the opponent's king. A checkmate occurs when a piece threatens to take the king on the next move (that is, the king is in "check"), and there is no legal move which gets the checked king out of check.

Chess is played on an 8 by 8 grid of alternating black and white squares (or, at least "light" and "dark"). The two players occupy opposite sides of the board. The starting position of Traditional Chess is always the same:

Each player has 16 pieces, but only 6 unique pieces:

	Pawns - There are eight pawns. They are the smallest pieces on the board. They move forward (toward the opponent's side of the board) one space at a time. However, if a pawn has not yet been moved, you have a choice of moving it one or two spaces forward.
	Rooks (also known as Castles) - There are two of these pieces, which usually resemble a castle tower. They move forward, backward, or sideways an unlimited distance along an unobstructed row or column.
	Bishops - There are two of these pieces, which usually resemble a bishop's mitre. They move diagonally an unlimited distance along an obstructed diagonal. One bishop starts on a white square and one on a black square and both will remain on that color square throughout the game (unless captured).
	Knights - There are two of these pieces, which usually resemble a horse's head. They make L-shaped moves, by moving to the opposite corner of a rectangle formed by any 2-by-3 set of squares. A knight is the only piece that does not require an unobstructed path; it can jump over an intervening piece of either color.
	Queen - There is only one queen. It is the second tallest piece, and is usually portrayed with a ball-topped crown. It combines the moves of the rook and the bishop; that is, it can move in any direction an unlimited number of spaces, until hitting the edge of the board or an obstruction.
	King - There is only one king. It is the tallest piece, and is usually portrayed with a crown topped by a cross. The king can move one piece in any direction. It cannot move into check; that is, it cannot move into a position where an opponent's piece can take it on the next turn.

Capturing an opponent's piece means removing it permanently from the board. You take an opponent's piece by moving your piece into the square occupied by the opponent's piece. For example, if your rook was in the same row as an opponent's bishop, and four spaces away and there were no intervening pieces, you could move the rook into the space occupied by that bishop, and capture it.

Pawns are an exception. They do not capture in the same way that they move. Pawns move forward one space, but they capture by moving diagonally forward one space. If a piece occupies the space in front of a pawn, that pawn is stuck and cannot move until the blocking pieces moves. However, if there was an opponent's piece on either side of that blocking piece, the pawn could move into the square and capture it.

There are several special moves in chess. The first of these is "castling"; it is the only time that two pieces can be moved on the same turn. The king moves two spaces toward one of the rooks, and the rook then jumps over the king to the first space after it. Castling can only be done if all the following are true:

The king has not yet been moved in this game
The rook that is being used to castle has not yet been moved in this game
All the spaces between the king and that rook are vacant
No enemy piece can move into a vacant space between the king and that rook
The king is not in check

Because of the first of those rules, no player can castle more than once during a given game. Castling is usually done to move the king into a more protected position, and to move a rook into a more useful, aggressive position.

Another special move is called "queening." If a pawn reaches the far end of the board, the player who controls that pawn may exchange it for any other type of piece. Usually, the player will choose a queen, since it is the most powerful type of piece. A player may choose a queen even if his/her original queen is still in play.

The third and final special move is called "en passant," a French phrase meaning "in passing." Let's say that a black pawn, on its first move, is moved two spaces forward, and this brings it directly next to a white pawn (that is, if the black pawn had moved only one space instead of two, it would have been in a position to be captured by the white pawn). The white opponent can move his/her pawn into the space that would have been occupied by the black pawn had it moved just one space instead of two, and remove the black pawn from the board. This is the only capture in the game where the capturing piece does not end up on the same square as the captured piece.

When your piece threatens to take an opponent's king on the next move, the king is said to be in "check". In a face-to-face game, it is customary to say "check" to your opponent at this point; in Chess Challenge, the game will display a message in the message area below the board. The player whose king is in check must immediately remedy the situation, either by moving the king, by moving a piece between the threatening piece and the king, or by taking the threatening piece.

If the checked king cannot be extricated, because it cannot be moved or because any move puts it into a square where it is similarly threatened, the king is not merely checked but is checkmated. The checkmated player loses the game.

Many chess games end before a checkmate, when one player realizes that defeat is inevitable and resigns the game. Many chess games end in a draw rather than a victory and defeat. There are several reasons why a game might end in a draw:

Agreement. Both players agree to end the game in a draw.

Stalemate. The player whose turn it is cannot make any legal moves, and yet that player's king is not in check. This usually occurs when the only move a player can make would move his/her king into check.

Repetition. The exact same arrangement of pieces occurs for the third time in a given game.

Lack of Force. There are insufficient pieces on the board for either player to checkmate the other. Example: when there are no pieces left other than the two kings.

Fischer Random Chess

Unlike Traditional Chess, the setup of the pieces varies with every game of Fischer Random Chess. The pawns setup is always the same as Traditional Chess, but the setup of the other pieces is randomized. (But not completely random: the bishops are always on different colors, and there is always a rook on either side of the king.) Both players have the same setup, so there is no advantage to either player.

Otherwise, the rules and piece movements are the same as for Traditional Chess. Note that the different setups can make for some unusual castling situations. Consult the two Castle buttons to the right of the chessboard to see whether your position allows castling at any given point.

Red Square Chess

Red Square Chess has the same piece setup as Traditional Chess. However, during each game of Red Square Chess, two of the unoccupied spaces in the center of the board will be red. These spaces will vary from game to game.

Pieces can pass over red squares, but only pawns can land there; all other pieces are barred from the red squares. Otherwise, the rules are exactly the same as for Traditional Chess.

Note that the king cannot move into a red square, even to avoid a check or checkmate.

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Clocks and Time Limits

When negotiating with a potential opponent, in addition to agreeing on a chess variation and on an entry fee, you need to agree to a time limit. At the start of the game, this time limit will be given to each player, and shown on the clock in the upper right corner of the Chess Challenge window. The clock will display time in both traditional and digital formats.

When it is your turn, your clock will count down, and your opponent's will be frozen. When you have made a move, your clock will freeze, and your opponent's will resume counting down.

If a player's time runs out before the completion of the game, that player loses.

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Rankings

All players start with a Chess Challenge ranking of 1500. Your ranking goes up when you win games, and down when you lose games. Your ranking remains unchanged when you draw a game. Also, your ranking is never affected by a Free or Practice game.

The magnitude of your rank change is based on three factors:

The rank of your opponent - your rank will go up more if you beat a higher-ranked opponent than if you beat a lower-ranked opponent. Similarly, your rank will go down more if you lose to a lower-ranked opponent than if you lose to a higher-ranked opponent.

Your previous rank - your rank change will get smaller as your rank gets higher. The entry fee for the game - the higher the entry fee, the greater the change in your rank.

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Ending the Game

To recap, you win a game of Chess Challenge if:

You place your opponent's king in checkmate.
Your opponent resigns.
Your opponent runs out of time.

A game will end in a draw if:

Both players agree to a draw.
The game reaches a stalemate.
The same arrangement of pieces occurs for the third time.
Neither player has sufficient force to checkmate the other.

Lack of Force. There are insufficient pieces on the board for either player to checkmate the other. Example: when there are no pieces left other than the two kings.

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Game Controls

Pieces are moved by clicking-and-dragging them. Click on of your pieces to pick it up. Keeping your mouse button depressed, drag the piece to your intended destination square, then release the mouse button. As soon as you release the mouse button, the move is recorded and your turn is over; your clock will stop, and your opponent's clock will resume.

If you have begun moving a piece, and you change your mind and want to move a different piece, just drag the piece back to its original square and release it.

If you try to move a piece to a square it is not allowed to move to - for instance, if you try to move a rook diagonally - the piece will snap back to its original square when you release it, and your turn will continue.

Once you have moved, you'll see the piece's original square outlined in blue and the piece's new square outlined in yellow; this allows you to easily see what move you just made. This same highlighting effect will be used to show your opponent's moves.

If you are able to castle on a given turn, one or both of the Castle buttons to the right of the chessboard will be lit up. If you want to castle, click the left button to castle leftward or the right button to castle rightward. If both buttons are grayed out, you are not able to castle at this time. You can also castle by moving your king two spaces toward the rook (except in certain setups of Fischer Random Chess, where the king does not move two spaces when castling); the game will realize that you're trying to castle, and will automatically complete the move by moving the rook for you.

If one of your pawns reaches the far side of the board, a dialogue box will pop up that will let you choose which piece you want to convert the pawn to.

Click the Resign button if you feel that your position is hopeless and you want to end the game without waiting for a checkmate.

Click the Draw button if you'd like to propose a draw. You can only do this during your turn. This does not propose a draw immediately; you must still complete your move. The draw will be proposed to your opponent immediately after your move is displayed to your opponent. If you decide to propose a draw, but then change your mind before making your move, just click the draw button again to cancel the action.

A log of game moves, in standard chess notation, is located below the Draw and Resign buttons. Once this list of moves gets too long to fit in the box, you can use the scroll bar to see the hidden part of the list.

Messages from the game will appear in the box immediately below the board. Messages from your opponent will appear in the chat window that you'll see just below the list of moves. If you want to send a message to your opponent, type it in the box below the chat window, and click the Send button. Note that this is a private chat; you and your opponent will be the only ones who will see these messages.

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Game Strategy

Strategy tips for chess are capable of filling volumes of books. If you're interested in becoming a very skilled chess player, we suggest that you seek out such books.

However, here are a handful of tips:

During the early part of the game, try to control the center area of the board. Move pieces into the center, or move pieces into position to protect the pieces in the center.

The most common opening moves are to move the king's pawn or the queen's pawn two squares forward.

As you move your pawn structure forward, try to keep the row staggered, so that the pawns to the rear protect the more forward pawns.

Notice that when you use a pawn to take another piece, it leaves two of your pawns in the same column of the board, which is a weak position - the rear pawn can no longer protect the front pawn, and there is a resulting "hole" in your line of pawns that your opponent can use to threaten your more important pieces.

Don't overreach - for example, don't move your bishop into an aggressive position by itself on your opponent's half of the board, where a simple pawn move will force it to retreat. Move your forces out steadily and evenly.

Sacrifice a less important piece in order to take a more important piece of your opponent's. Generally speaking, the order of importance of pieces, from most to least important, is queen, rook, bishop, knight, pawn. Some experts consider the knight and bishop to be of about equal worth. The king is not included on this list since it can never be taken.

Move a piece so that it threatens two of your opponent's pieces at the same time. That way, whichever piece the opponent moves out of harm's way, you'll be able to take the other. This is particularly effective when one of the threatened pieces is your opponent's king, as there is no choice in this case - your opponent must get the king out of check.

Try to anticipate your opponent's best move, and plan accordingly.

Balance offense and defense - don't concentrate entirely on one, to the detriment of the other.

Don't rush your moves, but also don't fall far behind your opponent on the time clock; this could put you in a terrible time bind toward the end of the game, forcing you to make unplanned moves, or worse, making you run out of time and lose the game.

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