If you can change a chess rule or create a chess rule, what would it be ?

Once per game, you may take a piece that is still on the board and place it back to its original (starting) position.

Amend 960 rules so that King is opposite Queen for both players. This will henceforth be known as Nobby Chess.

Lol. Bobby's Nobby

LoL!

5 times a game, you can sacrefice a piece (not a king) and the opponent must sacrefice a piece of the same value or more. (if your opponent has only a king then he does not sacrefice anything.)

move two queens onto the same square and it becomes a second king!

Ha! check out this link. It's an old forum about free-castling! Believe it or not this used to be part of the standard rules of chess until it got changed to the modern castling rules. The rules in free-castling are exactly the same as the modern castling rules (can't castle out of check, can't castle through check etc, etc) except that in free-castling the king doesn't have to go to g1 & the rook doesn't have to go to f1 (if you castle king-side). Free castling means that when one castles, the king & the rook can end up on various squares, e.g. the rook on e1 and the king on h1 for White in kingside castling, or the king could go to a1 (or b1, c1 etc, etc) & the Rook could go to e1 (or d1 or b1 etc) for queenside castling, these are just a few of the many permutations. Basically put, as long as the White king (for example) moves to the right of the rook for kingside castling, or to the left of the rook for queenside castling & the king and rook do not pass beyond their respective starting squares (e1 and h1 & e1 and a1) during this maneuver the move would be considered legal and playable. All other castling rules would still apply e.g. not castling through, into or out of a check and so forth. Once you've read the article you'll get a better idea of this very interesting rule.

article link Tim Harding's... Kibitzer

 http://chesscafe.com/text/kibitz31.txt

Old free-castling forum

http://www.chess.com/forum/view/general/bring-back-free-castling

 I would create a chess rule that would forbid any changes in the chess rules.

  I might be persuaded to go along with the "I always win" rule if it was immediately followed by the, no changes allowed rule.    

The 5 squares around the king is the 'King's Court' and no enemy piece can enter it (you can still choke him to checkmate via rooks/queen etc., they just must not step on those squares).

I would say a rule that allows a single pawn (if it has not moved) to be allowed to move two spaces left or right (if board permits), and/or to take an opposing piece if present. Move may not be performed to block a check and  is the only time the selected pawn may move for the remainder of game. I would call this "The Cassino Defense" named for the four battles by all, during the WWII "Battle of Monte Cassino"

Oh forgot most important part...may only be used when you have 4 pawns or less!

An 8x8 chessboard is arguably too small for amazon pieces. Moreover, an amazon can drive a king to the edge of the board an deliver checkmate on its own, so the balance would be shaken quite a bit more beyond what is immediately apparent.

From today's perspective, it is highly unlikely for any changes the core rules of the game (which excludes match/tournament regulations, etc.) to ever happen, given that there have been none anymore throughout the 20th century. The last change to the core game rules was the universal acceptance of en passant capture in the late 19th century. Any changes proposed thereafter have been accepted as "chess variants" at best (Capablanca chess, Fischerandom/960, Seirawan chess, etc.), any of which having had marginal success.

Play chess on an 8x8x8 grid. The first able to locate where the opponent's King is wins.

Seriously:, allow an artillery piece like the POW in Chinese Chess.

When the game is over the winner gets to mock the loser. Oh wait, I already do that!

You can sacrifice all your pieces (including your king) to create a Lord Xenu.

Lord Xenu has the properties of a Queen and Knight, and kills all ajacent enemy pieces to it.

[Note] This makes you lose due to your losing your King.

THE IRONY...

make a change , unless you take your opponent's king

promoted knight is a night rider