Instructions
Open "Minecraft," select "Single Player" from the options on the main screen, and then click "Create New World."
Enter a name for the world into the provided field, and then click "Game World: Survival" to toggle between Survival mode, Creative mode or Hardcore mode.
Click "Create New World" to start the game. Press "Esc" to bring up the Game menu, and then click "Open to LAN."
Set the game mode, click "Allow Cheats: Off" to toggle cheats on or off, and then click "Start LAN World."
Write down the IP address and port number displayed on the bottom of the screen, and then give this information to the other players on your LAN to enable them to join the game.