Load the script then type !Ngame in a channel to activate the "game". From there type !guess to guess the number. Upon guessing wrong you will be given a hint whether to guess higher or lower. Very simple script I made in a matter of minutes.

Update:
You can play through mIRC now by using /startgame and /guess

Can also retrieve the answer easier by typing /answer (Only use when your not playing because it obviously spoils the game :P)

//Number Game Script by [M]ike
//For Hawkee.com

on *:TEXT:!ngame:#: {
  if (%numgame [ $+ [ $chan ] ] != $null) {
    notice $nick A Number Game Is Already Running In $chan $+ ! Use !Guess Number To Guess A Number
  }
  else {
    set %numgame [ $+ [ $chan ] ] on
    msg $chan 7Random Number Game Started! The Number Is Between 1-200, Use !Guess Number To Guess A Number!
    set %num [ $+ [ $chan ] ] $rand(1,200)
  }
}
on *:TEXT:!guess*:#: {
  if (%numgame [ $+ [ $chan ] ] != on) {
    notice $nick There is no active number game in $chan $+ ! Use !Ngame to start one!
  }  
  elseif ($2 !isnum) {
    notice $nick " $+ $2 $+ " Is Not A Number.. Enter A Valid Number
  }
  elseif ($2 > 200) {
    notice $nick The Maximum Number Is 200, Guess A Lower Number
  }
  elseif ($2 != %num [ $+ [ $chan ] ]) && ($2 > %num [ $+ [ $chan ] ]) {
    msg $chan 7 $nick Was Wrong! Keep Guessing! 4Try A Lower Number!
  }
  elseif ($2 != %num [ $+ [ $chan ] ]) && ($2 < %num [ $+ [ $chan ] ]) {
    msg $chan 7 $nick Was Wrong! Keep Guessing! 4Try A Higher Number!
  }
  elseif ($2 == %num [ $+ [ $chan ] ])  {
    msg $chan 4 $nick Got It Right! The Answer Was $2 $+ ! Type !Ngame to play again.
    unset %num [ $+ [ $chan ] ]
    unset %numgame [ $+ [ $chan ] ]
  }
}

//Aliases so you can play through mIRC but with the channel, use /startgame and /guess <number>
alias startgame {
  if (%numgame [ $+ [ $active ] ] != $null) {
    echo -a A Number Game Is Already Running In $chan $+ ! Use !Guess Number To Guess A Number
  }
  else {
    set %numgame [ $+ [ $active ] ] on
    msg $active 7Random Number Game Started! The Number Is Between 1-200, Use !Guess Number To Guess A Number!
    set %num [ $+ [ $active ] ] $rand(1,200)
  }
}
alias guess {
  if (%numgame [ $+ [ $active ] ] != on) {
    echo -a There is no active number game in $active $+ ! Use /startgame to start one!
  }  
  elseif ($1 !isnum) {
    echo -a " $+ $1 $+ " Is Not A Number.. Enter A Valid Number
  }
  elseif ($1 > 200) {
    echo -a The Maximum Number Is 200, Guess A Lower Number
  }
  elseif ($1 != %num [ $+ [ $active ] ]) && ($1 > %num [ $+ [ $active ] ]) {
    msg $active 7 $me Was Wrong By Guessing $1 $+ ! Keep Guessing! 4Try A Lower Number!
  }
  elseif ($1 != %num [ $+ [ $active ] ]) && ($1 < %num [ $+ [ $active ] ]) {
    msg $active 7 $me Was Wrong By Guessing $1 $+ ! Keep Guessing! 4Try A Higher Number!
  }
  elseif ($1 == %num [ $+ [ $active ] ])  {
    msg $active 4 $me Got It Right! The Answer Was $1 $+ ! Type !Ngame to play again.
    unset %num [ $+ [ $active ] ]
    unset %numgame [ $+ [ $active ] ]
  }
}
//Answer alias - ONLY USE IF YOUR NOT PLAYING (Spoils the game)
alias answer {
  if (%numgame [ $+ [ $active ] ] == $null) {
    echo -a 5There is no number game running in $active
  }
  else {
    echo -a 4The answer to $active $+ 's number game is: 7 %num [ $+ [ $active ] ]
  }
}