WatfordFC: There might of been a piece already sitting on the spot where the one coming out would of ended up, if that was the case then it wont let you move one out.
(hide) If you want to play a game with an opponent of a similar level, you can define a required BKR range for a new game invitation. Then nobody with a BKR outside this range will be able to see/accept it. (Katechka) (show all tips)