It's funny-- except for Tenoke all the responses so far boil down to essentially this.
I'll try again.
Assume an alternate reality where this incredibly important rule doesn't exist. In it, the other player simply takes the king on the next turn from a neophyte who didn't realize they are still in check.
What bad things would happen as a result of the non-existence of the gratuitous rule?
And don't just speculate based on the zero cost of posting on HN. Give me the real reason based on the history of the creation of chess rules and/or the documented behavior of real chess players in history.
> Assume an alternate reality where this incredibly important rule doesn't exist. In it, the other player simply takes the king on the next turn from a neophyte who didn't realize they are still in check.
This is not merely an alternate reality; this is effectively the reality of blitz chess, where capturing the king is a way of claiming victory by declaring that the opponent made an illegal move when they didn't move out of check. In blitz chess you do not have the right to correct illegal moves after the opponent points them out.
If the penalty for the specific illegal move of not getting oneself out of check is to lose the game, what could the practical significance of the rule possibly be?
The other respondent is claiming that chess would become a game of "gotcha," as if the rule somehow prevents chess players from faking injuries to distract the chess ref and get free moves.
In regular chess, the rule just helps a player avoid one particular kind of blunder. Basically, it was arbitrarily decided that game records should never have king captures in them.
I would agree that makes it a poor excuse for a rule.
There is no immediate penalty, normally the opponent notices the illegal move and points it out, and the player has to undo the illegal move and continue with a legal move. Now if the player disobeys, then the opponent is able to declare the game forfeit.
An interesting edge case is if the opponent does not notice the illegal move. See FIDE for details.
Chess is a politically-themed wargame featuring monarchy. The King, being top kick, makes the rules of the land. Of course the King would enact such a rule that makes putting/leaving him in danger illegal.
Think about actual, medieval monarchs in their castles, holding literal absolute power over everyone. If someone were to invent a board game featuring a King, and the King were to be made aware that you moved him into danger and got him captured, he might have your head.
I feel as if I'm asking something fundamental that hasn't been considered by insiders. As if I asked music afficionados why Beethoven's Appassionata Sonata couldn't be performed in F-sharp minor and the response is something like, "Because arbitrarily changing the keys of sonatas would make a travesty of classical music, and performing the piece in F minor supports the preferences of the people who enjoy listening to classical music."
I don't know the history, but it's consistent with all the other rules, e.g. checkmate stops the game one move before the king is captured, stalemate occurs if the king would have to open himself up to capture, etc.
It's funny-- except for Tenoke all the responses so far boil down to essentially this.
I'll try again.
Assume an alternate reality where this incredibly important rule doesn't exist. In it, the other player simply takes the king on the next turn from a neophyte who didn't realize they are still in check.
What bad things would happen as a result of the non-existence of the gratuitous rule?
And don't just speculate based on the zero cost of posting on HN. Give me the real reason based on the history of the creation of chess rules and/or the documented behavior of real chess players in history.