When did chess rules last change?

Batgirl's thread on misconceptions

http://www.chess.com/forum/view/general/crazy-chess-beliefs

brings to mind this question: what was the last change in the rules of chess, and when did it occur?

I'm referring to changes in the play of a standard game (like en passant or how the bishop moves).  This isn't a quiz, since I don't know the answer.

The last additions to the standard game were near the end of the fifteenth century, although a few local variations have persisted.  In India, the two space first move wasn't introduced, which is why we have the King's Indian opening that features a one step move.  In some places, pawn promotion was only allowed to a piece that had previously been captured, i.e. no  two queens allowed.  The rules as we know them were made more or less universal when international tournaments began in the 19th century.

A bit of clarification here courtesy of a post by Blunderprone:

http://blog.chess.com/Blunderprone/a-historical-perspective-on-the-study-of-pawn-formations

"in 1862, at the London Congress, it was determined that when a pawn advances to the 8th rank, it no longer was held as a “dummy piece” until the right piece was captured to replace it. It was allowed to become any piece immediately."

I just read in a book by Raymond Smullyan, a logician.  I forget the name of the book but it is a series of "forensic chess puzzles" solved by Sherlock Holmes.

Anyway, according to Smullyan, the last official change in rules occurred in the 1800s.  The previous rule stated that a promoted pawn could become any piece except the king or a pawn.  The rule had to be amended, stating that a promoted pawn could become any piece of the same color, except the king or a pawn.  The rule change was precipitated by a famous game that ended similar to this:

White has an obvious advantage here but shouldn't be able to mate in one.  Whatever white promotes to on b8, black's king can capture it.

Except...white played b8, promoting to a black knight!  Not illegal, according to the rule book at the time

But if I remeber well, in 90' FIDE temporarily changed 50-move draw rule for certain endgames (e.g. 2xB vs N) when endgame databases proved checkmating can take longer. Later it was changed back.

The last rule change was actually in 2014, with the introduction of the 75-move rule and fivefold repetition. If 75 moves pass without a capture or pawn move and the game has not otherwise ended, the game is a draw. If a position (beyond just the location of the pieces) occurs five times, the game is a draw.

Thanks for the information

Just came back here. I actually didn't notice that this thread was older than that rule change. HOW

As late as 1889, Black had the option to move first. Play had been gradually moving toward having White go first, but that didn't become solidified until around 1889-90. Check Wikipedia.

Never mind; apparently the last rule change was in 2017 to remove the consecutiveness requirement for a game to end in fivefold repetition.

Chess rules changed back when chess.com was founded when they fabricated the fake onpondosdont rule. This is a glitch, hack, and scam!

And don't even get me started on this "steal bait" irregularity. 

Interesting thread.

--- Yup.