The Slow Decay

The world is covered in radiation and things affected by radiation. The survivors were forced underground. There, they made their own forces, split into two branches. The Execution Forces move up and scavenge for anything useful and eliminate threats. The Protective forces guard and secure anybody inside the underground bases. Today is your eighteenth birthday. Your loved ones should be happy, but instead, they're sad because you must sign for the forces. There's a good chance you won't last long. No one ever does.