> [...] > How can I distribute all 25 letters (I will skip the "J" for this) > over a 5x5 matrix (two dimensional array) that way, that each letter > is handled equally from the statistical point of view ? Hi Christian, you got some answers already, but of course there is always another fun way to do stuff with ruby: letters = [*('A'..'Z')] - ['J'] p (0...5).map{(0...5).map{letters.slice!(rand(letters.size))}} cheers Simon