my %effects = (
  part => [qw(acid cold electricity fire)],
  gaze => [qw(paralysis stone stun death)],
  range_part => [qw(gas sonic)],
  touch_part => [qw(poison energy_drain)],
  touch_special => [qw(befouls purifies nullifies_holy_water nullifies_unholy_water)],
  vocal => [qw(deafen fear terror flight)],
);

$effects{'range'} = [@{$effects{'part'}}, @{$effects{'range_part'}}];
$effects{'touch'} = [@{$effects{'part'}}, @{$effects{'touch_part'}}];
$effects{'general'} = [@{$effects{'part'}}, @{$effects{'gaze'}}, @{$effects{'range_part'}}, @{$effects{'touch_part'}}, @{$effects{'vocal'}}];

sub random_effect {
  my $type = shift;
  my $result;
  if (exists $effects{$type}) {
    $result = $effects{$type}[rand @{$effects{$type}}];
  }
  else {
    $result = $effects{'general'}[rand @{$effects{'general'}}];
  }
  $result =~ tr/_/ /;
  return $result;
}