UNAUTHORIZED PRODUCTION The information that BGG has on this item indicates that Blokád is a non-authorized version of Blokus. An unauthorized version of Blokus, where players are trying to play onto the board transparent, Tetris-shaped, colored pieces. The only caveat to placing a piece is that it may not lie adjacent to your other pieces, but instead must be placed touching at least one corner of your pieces already on the board. The main differences between Blokus and this game is that everything is made of cardboard here (so you can't flip the tiles) and a few pieces are different.