something like this? (assuming it is a tetris clone you are coding)
' psuedo code... for x = 0 until 4 for y = 0 until 4 if a_block[ block_type, rotation, x,y] <> 0 then if the_playing_field[ blockX+x, blockY+y ] <> 0 then ' BAM! This block collided with the ones already placed. endif endif next next