Completely negates all damage. You can walk through a hail of gunfire, step on landmines, or fall from great heights without a scratch. This is the essential option for learning level layouts or just enjoying a power trip.
Prevents enemies from detecting you, making stealth missions trivial.
Walk past guards and security cameras undetected.
Once in a mission, use the Hotkeys (usually F1 through F12 or the Numpad) to toggle your desired cheats. Why Use the +13 Trainer?
