cupcake, try using the goto command. It saves you the if conditions.

alias slap {
  var %m describe #
  goto $r(1,11)
  :1 | %m $1 around a bit with a large trout. | halt
  :2 | %m slaps $1 with a television. | halt
  :3 | %m slaps $1 with room`s door. | halt
  :4 | %m giggles at $1. | halt
  :5 | %m nudges $1. | halt
  :6 | %m pokes $1 with a birthday cake. | halt
  :7 | %m spanks $1. | halt
  :8 | %m burns $1 hard. | halt
  :9 | %m pokes $1 with his leg. | halt
  :10 | %m tickles $1. | halt
  :11 | %m beats $1 senseless with a wet noodle. | halt
}

And you don't need to use $+ when it comes to placing punctuation marks after the $1 or $2 etc...