nabla: 1. Triple check is possible. Yet very rare in practice.
2. The rule gets very interesting in combination with rule 1. If you can only put your piece in play with a normal check, the opponent can take it off the board by promoting a pawn! :D In my region bugchess is nearly always played with the combination of these two rulez!
rabbitoid: If the opponent has only a king and pawns left, a promoted pawn is simply removed from the board!
Rule (2) comes often into play. Early checkmates with dropped pawns/bishops on f2/f7 can be prevented by blocking the own king. This is no beginners rule but quite an interesting defense possibility. Besides checkmating is often too easy by dropping a queen.
(gem) Hvis du vil spille et spil med en modspiller som er på omtrent samme niveau kan du lave en invitation med et ønsket BKR-område. Da kan kun de spillere med den BKR se og acceptere invitationen. (Katechka) (vis alle tips)