return function(mod)
  local blocks = {}
  for i = 1, 30 do blocks[i] = 10 end
  blocks[8], blocks[9] = 11, 11 -- the two grass blocks
  local pallet = mod.content.maps:get("PALLET_TOWN")
  local palletBlocks = {}
  for i, block in ipairs(pallet.blocks) do palletBlocks[i] = block end
  palletBlocks[7 * pallet.width] = 10 -- block (9, 6), lower-right exit

  mod.content.maps:register("TUTORIAL_ROUTE", {
    id = "TUTORIAL_ROUTE", label = "TutorialRoute", index = 1000,
    tileset = "OVERWORLD", width = 6, height = 5, blocks = blocks,
    borderBlock = 10, connections = { west = { map = "PALLET_TOWN", offset = -2 } },
  })
  mod.content.maps:patch("PALLET_TOWN", {
    connections = { east = { map = "TUTORIAL_ROUTE", offset = 2 } },
    blocks = palletBlocks,
    objects = { __append = {
      {
        index = 90, x = 8, y = 7, sprite = "SPRITE_BEAUTY",
        movement = "STAY", range = "NONE", text = "TEXT_TUTORIAL_WORLD",
        name = "TUTORIAL_WORLD_NPC",
      },
    } },
  })
  mod.content.map_scripts:register("PALLET_TOWN", {
    talk = { TEXT_TUTORIAL_WORLD = {
      { "face_player" }, { "show_text", "Welcome to the\nTutorial World!" },
    } },
  })
  mod.content.encounters:register("TUTORIAL_ROUTE", {
    grass = { rate = 25, slots = {
      { species = "PIDGEY", level = 3 }, { species = "RATTATA", level = 3 },
      { species = "PIDGEY", level = 4 }, { species = "RATTATA", level = 4 },
      { species = "PIDGEY", level = 5 }, { species = "RATTATA", level = 5 },
      { species = "PIDGEY", level = 3 }, { species = "RATTATA", level = 3 },
      { species = "PIDGEY", level = 6 }, { species = "RATTATA", level = 6 },
    } },
  })
end