Well looking at the rules of Ludo on wikipedia, it says that a roll of a six earns a bonus roll. I did not see where it says in there that the bonus roll MUST be used with the same pieces that the original 6 was moved with, and in addition to that if the bonus roll can not be used, the original 6 is now void.
(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)