Ruby | Rock Paper Scissors

rockPaperScissors.rb

gameIsRunning   = true
$score_computer = 0
$score_player   = 0
$score_ties     = 0
showScore       = false
choices         = ["rock", "paper", "scissors"]

def start
  puts "--------------------------------------------------------"
  puts "        R O C K   P A P E R   S C I S S O R S           "
  puts "--------------------------------------------------------"
  puts " - CREATED BY                                   CRITICAL"
  puts "  "
  puts "There once was a young boy who lived peacfully with his
      \rfamily. His family always struggled with money, but one
      \rday that all changed. He was challenged by a robot to
      \rplay the classic game \"Rock Paper Scissors\". If the boy
      \rone the robot would print him $100,000,000, so he
      \raccepted challenge.
      "
end


def menu(x=nil)
  system "clear" or system "cls"
  start() if x == "start"
  puts "--------------------------------------------------------"
  puts "                   H E L P   M E N U                    "
  puts "--------------------------------------------------------"
  puts " - H,  HELP                         Show the help screen"
  puts " - P,  PAPER                        Choose paper        "
  puts " - Q,  QUIT                         Quit the game       "
  puts " - R,  ROCK                         Choose rock         "
  puts " - S,  SCISSORS                     Choose scissors     "
  puts ""
end

def score()
  system "clear" or system "cls"
  puts "--------------------------------------------------------"
  puts "                 S C O R E   B O A R D                  "
  puts "--------------------------------------------------------"
  puts " - PLAYER                          #{$score_player}     "
  puts " - COMPUTER                        #{$score_computer}   "
  puts " - TIES                            #{$score_ties}       "
  puts ""
end

# determine who the winner is.
# winner = what the computer needs to be to win.
# tie = what the computer needs to be to tie.
def winner?(winner, tie)
  if $computer == winner
    $score_computer +=1
  else
    $computer == tie ? $score_ties +=1 : $score_player +=1
  end
end

menu("start")
while gameIsRunning do
  score() if showScore
  print "> "
  $player = gets.chomp.downcase
  $computer = choices[Random.rand(3)]



  case $player
  when "rock", "paper", "scissors", "r", "p", "s"
    system "clear" or system "cls"
    showScore = true

    winner?("paper", "rock")     if $player == "rock"     || $player == "r"
    winner?("scissors", "paper") if $player == "paper"    || $player == "p"
    winner?("rock", "scissors")  if $player == "scissors" || $player == "s"

  when "quit", "q"
    showScore = false
    gameIsRunning = false
  when "help", "h"
    showScore = false
    menu()
  else
    puts "THIS IS NOT AN OPTION.\nUse  'H' or 'HELP' to get help.\n"
  end


end

system "clear" or system "cls"
puts "--------------------------------------------------------"
puts "               S E E   Y O U   S O O N                  "
puts "--------------------------------------------------------"
puts ""
sleep 1
system "clear" or system "cls"