Some random experiments

test1.rb

class Player
  def initialize(name)
    puts "-1- self.name object_id => #{self.name.object_id}\n\n"

    puts '[initialize] self.name = name'
    self.name = name
    puts "-2- @name object_id => #{@name.object_id}, self.name object_id => #{self.name.object_id}\n\n"

    puts '[initialize] @name = name'
    @name = name
    puts "-3- @name object_id => #{@name.object_id}, self.name object_id => #{self.name.object_id}\n\n"

    puts "[initialize] @name = 'another name'"
    @name = 'another name'
    puts "-4- @name object_id => #{@name.object_id}, self.name object_id => #{self.name.object_id}\n\n"
  end

  def change_name(name)
    puts '[change_name] @name = name'
    @name = name
    puts "-5- @name object_id => #{@name.object_id}, self.name object_id => #{self.name.object_id}\n\n"

    puts '[change_name] self.name = name'
    self.name = name
    puts "-6- @name object_id => #{@name.object_id}, self.name object_id => #{self.name.object_id}\n\n"
  end

  attr_accessor :name
end

# ---

player = Player.new('A name')
player.change_name('A new name')

<<~OUTPUT
  -1- self.name object_id => 8

  [initialize] self.name = name
  -2- @name object_id => 60, self.name object_id => 60

  [initialize] @name = name
  -3- @name object_id => 60, self.name object_id => 60

  [initialize] @name = 'another name'
  -4- @name object_id => 80, self.name object_id => 80

  [change_name] @name = name
  -5- @name object_id => 100, self.name object_id => 100

  [change_name] self.name = name
  -6- @name object_id => 100, self.name object_id => 100
OUTPUT

test2.rb

class Player
  def initialize(name)
    puts "-1- @name object_id => #{@name.object_id}\n\n"

    puts '[initialize] @name = name'
    @name = name
    puts "-2- @name object_id => #{@name.object_id}, self.name object_id => #{self.name.object_id}\n\n"

    puts '[initialize] self.name = name'
    self.name = name
    puts "-2- @name object_id => #{@name.object_id}, self.name object_id => #{self.name.object_id}\n\n"

    puts "[initialize] self.name = 'another name'"
    self.name = 'another name'
    puts "-4- @name object_id => #{@name.object_id}, self.name object_id => #{self.name.object_id}\n\n"
  end

  def change_name(name)
    puts '[change_name] self.name = name'
    self.name = name
    puts "-5- @name object_id => #{@name.object_id}, self.name object_id => #{self.name.object_id}\n\n"

    puts '[change_name] self.name = name'
    @name = name
    puts "-6- @name object_id => #{@name.object_id}, self.name object_id => #{self.name.object_id}\n\n"
  end

  attr_accessor :name
end

# ---

player = Player.new('A name')
player.change_name('A new name')

<<~OUTPUT
  -1- @name object_id => 8

  [initialize] @name = name
  -2- @name object_id => 60, self.name object_id => 60

  [initialize] self.name = name
  -2- @name object_id => 60, self.name object_id => 60

  [initialize] self.name = 'another name'
  -4- @name object_id => 80, self.name object_id => 80

  [change_name] self.name = name
  -5- @name object_id => 100, self.name object_id => 100

  [change_name] self.name = name
  -6- @name object_id => 100, self.name object_id => 100
OUTPUT