#right click on cmd.exe and press run as administrator.
#In cmd.exe, type: <code>
mklink /d %appdata%\.minecraft\ saves <dropbox_path>\Minecraft\saves </code>
#The console will output “Symbolic link created” if everything succeeded.
(This is tested to work on Windows 7. It has also been tested in Windows 8.1 using this method and is not working properly, if you would like to use it on this OS, you will need to put your world saves directly in your Dropbox folder and edit the file path in the code to reflect the change.)
=== Mac OS X ===