No need for a global set variable here.
Use a local variable to avoid harddrive writes and reads.
ANYWHERE $chan works the short form # will work.
The main reason $chan exist is for doing more elaborate
things like $chan(0) $chan(#).topic etc etc
$r(1,6) is short for $rand(1,6)
This should be in a nicklist popup because of $1

menu nicklist {
  Random Slap $$1:slap $1
}
alias slap {
    var %r $r(1,6)
    if %r == 1 { describe # slaps $1 around a bit with a large trout. }
    if %r == 2 { describe # slaps $1 with a television. }
    if %r == 3 { describe # slaps $1 with a fish. }
    if %r == 4 { describe # slaps $1 with a pair of sunglasses. }
    if %r == 5 { describe # bitch slaps $1 $+ . }
    if %r == 6 { describe # slaps $1 with a birthday cake. }
}