Play Minecraft over LAN - so it'll work
Since version 1.6 "Minecraft" you can easily play with other people via LAN. You can find out how this works here.
Start Minecraft LAN server
- Start the Minecraft game as usual.
- Select "Singleplayer" and start the world you want, or create a new one.
- Click the "Escape button" in the game and then select "Open for LAN".
- Adjust the settings and click "OK".
- The server is now started. A message appears in the chat via which port the server is running.
Join the Minecraft LAN server
- Open the Minecraft game.
- Click on "Multiplayer".
- After a short time, the server should appear in the list. Select it and click on "Join".
- If that doesn't work, check your firewall to see if it is blocking Minecraft and the additional "server process". You can also temporarily completely disable the firewall. You can find out how this works here.
Tip: You can also activate cheats for Minecraft on your LAN server.