The Ruin RPG will utilise D&D 5th Edition rules and a percentile system with a few tweaks to fit an apocalyptic world. This will include bringing new backgrounds, new origins. and new classes to the game. A complete crafting and gear section and a section on the world of The Ruin. The core book will be a complete rule book and you will need nothing else to play, except for some dice, pencils and friends.
There is a quick start available on DrivethruRPG which you can find by clicking >Here<