Chess- King and rook crossing over!?

Playing chess against the computer, the computer's back line looks like this:



R K B Q K _ _ R



Then it makes one move, but moving two peices where the king and the right rook cross over eachother, to look like this:



R K B Q _ R K _



Is this a rule? ThanksChess- King and rook crossing over!?
It is a rule, called "castling." You cannot castle when in check, or if the king will pass over any square that is attacked. You cannot castle if your king has ever moved, nor if the rook you're castling with has moved. You can castle to either side if there are no pieces between the king and rook: on the king's side, it's called "castling short" while on the queen's side it's called "castling long."



To perform castling, move the king two squares toward the rook. Then, jump the king with the rook (a computer program will perform this jump for you, inferring from the two-square king move that you are trying to castle.)
It is called "Castling". The following should help explain the move, requirements and the purpose:



Castling is a special move in the game of chess involving the king and either of the original rooks of the same color. It is the only move in chess (leaving aside promotion) in which a player moves two pieces at the same time. Castling consists of moving the king two squares towards a rook on the player's first rank, then moving the rook onto the square over which the king crossed.[1] Castling can only be done if the king has never moved, the rook involved has never moved, the king is not in check, and the king does not cross over or end on a square in which it would be in check. Castling is considered a king move.



Castling is permissible if and only if all of the following conditions hold:



1.The king has not previously moved;

2.The chosen rook has not previously moved;

3.There must be no pieces between the king and the chosen rook;

4.The king is not currently in check.

5.The king must not pass through a square that is under attack by enemy pieces.

6.The king must not end up in check (true of any legal move).

7.The king and the chosen rook must be on the same rank.



Castling is an important goal in the early part of a game, because it serves two valuable purposes: it moves the king into a safer position away from the center of the board, and it moves the rook to a more active position in the center of the board (it is even possible to checkmate with castling).



The choice as to which side to castle often hinges on an assessment of the trade-off between king safety and activity of the rook. Kingside castling is generally slightly safer, because the king ends up closer to the edge of the board and all the pawns on the castled side are defended by the king. In queenside castling, the king is placed closer to the center and the pawn on the a-file is undefended; the king is thus often moved to the b-file to defend the a-pawn and to move the king away from the center of the board. In addition, queenside castling requires moving the queen; therefore, it may take slightly longer to achieve than kingside castling. On the other hand, queenside castling places the rook more effectively 鈥?on the central d-file. It is often immediately active, whereas with kingside castling a tempo may be required to move the rook to a more effective square.



It is common for both players to castle kingside, and rare for both players to castle queenside. If one player castles kingside and the other queenside, it is called opposite castling. Castling on opposite sides usually results in a fierce fight as both players' pawns are free to advance to attack the opposing king's castled position without exposing the player's own castled king. An example is the Dragon Variation of the Sicilian Defence.



If the king is forced to move before it has the opportunity to castle, the player may still wish to maneuver the king towards the edge of the board and the corresponding rook towards the center. When a player takes three or four moves to accomplish what castling would have accomplished in one move, it is sometimes called artificial castling, or castling by hand.



Hope that helps!Chess- King and rook crossing over!?
this rule is called "castling"



it's 100% legal



this rule is about 1000 years old



you can even go go the other way...its called "queenside-castling"



but there ARE a few more rules attached....



1) you cant castle out-of-check

2) you cant castle into-check

3) you cant castle cross-check



4) if the king was moved earlier? you cant castle

5) if the rook was moved earlier? you cant castle (but you can go the other way)



i know there are a lot of rules...but like i said...its 100% legal
It is called castling and done when there are no pieces between them. Both the King and the Rook may not have moved before and you can't move into, out of, or through check.Chess- King and rook crossing over!?
It is very much a viable move. And ive seen it used quite a few times. Making the king slightly more protected but also cornering him.
Yes, it is called "castling", it can be effective