function state_rules()
  local fade = split "0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,2,4,9,10,9,4,2,1"
  local color = 1

  local function blink(x, y, w, h)
    rect2(x, y, w, h, fade[color])
  end

  local function go_back()
    set_state(states.menu)
  end

  local btn_back = make_button({
    x = 1, y = 118, w = 30, h = 7, text = "🅾️/C mENU", color = 8,
    on_click = function() go_back() end,
    on_hover = function(btn) btn.color = 7 end
  })

  return {
    _enter = function()
    end,

    _exit = function()
      -- standard_font()
    end,

    _update = function()
      -- custom_font()
      if frame_count % 8 == 0 then
        color += 1
      end
      if color > #fade then
        color = 1
      end

      -- Back to the menu
      if btnp(BTN_O) then
        go_back()
      end

      btn_back:update()
    end,

    _draw = function()
      cls()

      print("1) yOU CAN'T HAVE MORE THAN\n   TWO (2) CONSECUTIVE TILES\n   OF THE SAME COLOR", 2, 2, 7)
      local x = 14
      local y = 28
      sspr(0, 32, 12, 12, x, y)
      spr(2, x + 14, y + 1)
      sspr(13, 32, 12, 12, x + 26, y)
      blink(x - 1, y - 1, 9, 3)
      blink(x + 25, y - 1, 9, 3)
      blink(x - 1, y + 8, 12, 3)
      blink(x + 25, y + 8, 12, 3)

      x = 75
      sspr(26, 32, 12, 12, x, y)
      spr(2, x + 14, y + 1)
      sspr(39, 32, 12, 12, x + 26, y)
      blink(x + 5, y + 2, 3, 9)
      blink(x + 31, y + 2, 3, 9)

      --------------

      x = 44
      y = 50
      print("2) eACH LINE CONTAINS AN EQUAL\n   NUMBER OF EACH COLOR", 2, y, 7)
      sspr(52, 32, 12, 12, x, y + 20)
      spr(2, x + 14, y + 21)
      sspr(65, 32, 12, 12, x + 26, y + 20)
      blink(x + 5, y + 22, 6, 3)
      blink(x + 31, y + 22, 6, 3)
      blink(x - 1, y + 19, 3, 6)
      blink(x + 25, y + 19, 3, 6)

      --------------

      x = 44
      y = 90
      print("3) aLL ROWS AND COLUMNS\n   ARE DIFFERENT", 2, y, 7)
      sspr(78, 32, 12, 12, x, y + 20)
      spr(2, x + 14, y + 21)
      sspr(91, 32, 12, 12, x + 26, y + 20)
      blink(x - 1, y + 25, 12, 6)
      blink(x + 25, y + 25, 12, 6)

      --------------

      btn_back:draw()
    end
  }
end