Code:
on *:text:!spin:#: {
flood spin 600
var %r $+($iif($r(1,2) == 1,+,-),$r(1,250))
msg # $upper($nick) received %r points!
}


alias flood {
  if (YOURNICK !isin $1-) {
    if ($1 !isnum) {
      if ($($+(%,flood.,#,.,$1),2)) { echo 4 # Flood control | halt }
      set -z %flood. $+ # $+ . $+ $1 $2 
    } 
    else {
      if ($($+(%,flood.,#),2)) { echo 4 # Flood control | halt }
      set -z %flood. $+ # $1 
    }
  }
}
Untested