Scary Craps

scary_craps.rb

class Die
  def roll_die
    rand(1..6)
  end
end

class CrapsGame
  attr_accessor :point, :dice_roll

  def pass 
    (@dice_roll == 7 || @dice_roll == 11)
  end

  def no_pass 
    @dice_roll == 2 || @dice_roll == 3 || @dice_roll == 12
  end

  def craps
    @dice_roll == 7
  end

  def win
    @dice_roll == @point
  end

  def roll (die1, die2, first_roll)

    self.dice_roll = die1.roll_die + die2.roll_die

    if first_roll

      puts "your first roll was a #{@dice_roll}"

      if pass
        puts dice_roll
        puts "'natural' roll, you WIN!"

      elsif no_pass
        puts dice_roll
        puts "'craps!' you LOSE!"

      else
        self.point = dice_roll
        puts "set point is #{@point}"
        roll(die1, die2, false)
      end

    else

      puts "rolling again and you rolled a #{@dice_roll}"

      if craps
        puts "you crapped out with a #{@dice_roll}"
      elsif win
        puts "you win with #{@point}"
      else
        roll(die1, die2, false)
      end

    end
  end
end

CrapsGame.new.roll(Die.new, Die.new, true)

I was looking at the @dice_roll and the @point v. using self.dice_roll and self.point. I thought maybe using self. for setting seemed ok and @ for retrieving, but I'm not sure about that and if there is a big difference other than style??