A chess vampire is a legal position "without a mirror image", i.e.
whose mirror image is illegal.
Visit
this post
for a precise definition of "positon" and "mirror image" and for more details about the
exciting world of chess vampires.
Here you can explore the tree of vampires of the first clan, named
KQkq.
That is, vampires where all castling rights are still enabled.
Red moves indicate that the position will remain a vampire after played (they preserve the parity
invariant), while green moves lose the vampiric property. Moves that alter the castling rights
are colored in gray.
You can use the left and right arrows on your keyboard to move back and forth in the last variation
you introduced.