dip.rb

class Game
  attr_accessor :player_one, :player_two, :board, :game_over, :difficulty_level, :ai, :ui
  def initialize(board)
    @board      = board
    @ui         = UI.new(@board)
    @player_one = Player.new('X', get_player_type('X'), @board)
    @player_two = Player.new('O', get_player_type('Y'), @board)
    @player_one.opponent = @player_two
    @player_two.opponent = @player_one
    @game_over  = false
    @ai         = AI.new
    @difficulty_level = get_difficulty_level
  end
 
  def get_difficulty_level ## Moved to the GameSetup class
    return nil unless player_one.player_type == 'computer' || player_two.player_type == 'computer'
    ui.difficulty_level_message
    level = gets.chomp.downcase
    validate_level(level)
  end
...
end