From the back of the book: Lady Luck...she is a fickle mistress. Why not take her out and get her something nice? Actually, she better be in a hot bath with a glass of wine while you are rubbing her feet, because with "The Devious Book of Fumbles & Crits," if you roll a "1" she can make your life a living hell...literally. A 4E D&D Supplement for all levels. 20 Fumbles & 20 Criticals For Magic-Using Players. 20 Fumbles & 20 Criticals For Melee Or Ranged Players. 20 Fumbles & 20 Criticals For The Monsters Too! Turnabout Is Fair Play. Optional Quick Balancing Tools & 40 "Quick Fumbles" for a total of 120 Fumbles/Crits. Rich & Detailed Encounter Add-Ins: 22 New Creatures (unique minions) 63 New, Unique Treasures, Including 6 Item Sets 28 New Hazards & Terrain Powers New Diseases, Crazy Potions & Poisons