(26.03.2013) A fairy problem from Themis Argirakopoulos (Greece) with interesting combination of KoBul Kings and Circe Cage.

a) 1.Sd5 Sxd5(+bSb6)(bK=rS)+ 2.rSa8 Sxb6(+bSc7)#

b) 1.Bd6 Bxd6(+bBe7)(bK=rB)+ 2.rBd8 Bxe7(+bBc7)#

c) 1.Kc8 Rxc4(+bRg8)(bK=rR)+ 2.Sxc4(+wRh8)(wK=rR) Rxg8(+bRc6)#

An aristocrat miniature with Forsberg twins, showing that bK can not

defend himself because capturing the mating piece, creating a cage for

white to rebirth! (Author)

KoBul Kings: When a piece (not a pawn) of his own side is captured, a King transforms into a Royal piece of the same type as the captured one. When the King is in the form of any Royal piece and there is a capture of one of the pawns of his own side, he becomes a normal King again.

Circe Cage:

   1. Captured pieces are reborn if there is one or more rebirth squares for the captured piece. When there are none, the captured piece is denitively removed from the board. As kings can not be captured, checks and mates are orthodox.
   2. Rebirth squares are called cages. A cage for a given piece is a square such that if the given piece lied on that square, its only legal moves would be captures.
   3. When there are more than one cage, the side making the capture chooses the rebirth square from the available cages.
   4. Cages are determined after the capture has taken place.
   5. White pawns may reborn on the 1st row, from which they can move like ordinary pawns, including making a double step from the second row. Same for black pawns.
   6. White pawns may also reborn as promoted pieces on the last row. In such case, the rebirth square must be a cage for the promoted piece, the type of which is choosen by the side making the capture. Same for black pawns.
   7. A reborn piece is "brand new"; its move history is lost. For example, a white rook reborn on h1 retrieves the ability to castle.