The HARDEST Achievement in Call of Duty History? - Black Ops 3's Personal Decorator

Arguably Call of Duty's toughest challenge if you're a trophy or achievement hunter, and the reason most people never 100% or platinum Black Ops 3... Welcome to the absolute nightmare that is the Personal Decorator achievement. I've played a lot of Call of Duty games in my time and earned a lot of their achievements, but the general consensus is that Black Ops 3's Personal Decorator takes the crown of the hardest achievement in any Call of Duty game. 3+ full campaign playthroughs, 20000+ kills, multiple difficulty achievements, collectibles... It doesn't sound that bad, right? Only one way to find out I suppose!