Spell Fumble Table (d100): d100 Result 01–05 Spell backfires: you take half of its damage (or 1d6 per spell level if non-damaging). 06–10 Arcane surge: roll on the Wild Magic Surge table (if available). 11–15 Spell fizzles: slot is expended, no effect. 16–20 Magical feedback: you are stunned until the start of your next turn. […]
Melee Fumble Table (d100): d100 Result 01–05 You strike yourself: roll damage against your own AC. 06–10 You overextend and fall prone. 11–15 Weapon slips from your hand: lands 1d6 × 5 ft away. 16–20 Stumble into danger: nearest enemy gains an Opportunity Attack. 21–25 Critical misstep: you fall prone and provoke Opportunity Attacks from […]
When you score a CRITICAL HIT with a SPELL ATTACK, you deal: Example:A Fireball (8d6) would deal:
Example:The weapon normally deals 2d8 damage. The damage roll would be: 8 + STR MOD + STR MOD + 1d8, with the ability to reroll one of those 1d8.