Soo, this could be possible?
Bring Back Free Castling!

It kind of makes sense. To wit: if the monarch runs into the castle why should we know beforehand which "room" (square) he will hide in?

The best rule change idea I've ever seen.
But that's not saying I necessarily think it's a good idea.
There's a really interesting article on chesscafe.com titled Bring Back Free Castling! that's in the archives section for The Kibitzer column which is written by Tim Harding. It argues that modern castling rules should be changed back to the old "free castling" rules. 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. Harding argues that this rule would make chess even more interesting and would add more dynamism & strategy without radically altering the character of the game or board like so many chess variants do. (bughouse chess, progressive chess, 3-D chess, loser's/suicide/giveaway chess, Fischer random/chess360 etc) And just to reiterate, free castling was the standard way of castling before the modern rules were introduced & the old Italian rules were let go, so changing the rules is not as radical as some would think. Check out the article and post your thoughts! Here's the link to the article on free castling.
http://www.chesscafe.com/text/kibitz31.txt