@guesses and the next OUTER were making it ignore guesses that had already been given instead of counting them as right or wrong. It would have been better to use a %guesses hash for that:

          ...
          $guess=<STDIN>;  chomp $guess;
          next if $guesses{$guess}++;
          $right=0;
          ...
[download]

but this program seems blithely ignorant of the existence of hashes.

If you feel daring, take a look at the severely undercommented word twist for a more hash-ridden implementation of a word game.