Go to the developer console by hitting ~ (or the key above Tab) and type the following codes for the desired effect. This will allow you to open the cheating console. To begin you must first go to the 'Options' on your game menu and select the 'Keyboard' tab, then select 'Advanced.', Finaly you check off the 'Enable Developer Console (~)' and select 'Ok' and select 'Apply' on your 'Options' menu. Upon the release of GMod 13, the secret phrase was changed to bloxwich.
