Yanfly Engine Plugins is a plugin library made for RPG Maker MV, a wonderful piece of software to help you make that role playing game of your dreams. You can find out more about RPG Maker MV here.
Magic Guard is a passive ability from Pokémon that prevents indirect damage dealt from states such as Poison. With this Tips & Tricks, you can recreate the effect in MV, too!
Get the copy/paste version of the code here: