  "Solitaire Chess" is a logic puzzle published by Thinkfun, that can be seen
as a single person version of traditional chess. Given a chess board with some
chess pieces of the same color placed on it, the task is to capture all pieces
but one using only moves that are allowed in chess. Moreover, in each move one
piece has to be captured. We prove that deciding if a given instance of
Solitaire Chess is solvable is NP-complete.
