I ' ve read that firestorms explosion AOE is radius 12 and the falling radius is 25 , which means that the chance of hitting a point i . e . a target with no added radius is 1225 48 % which means you ' ll be hitting 910 balls in the worst case scenario as any extra radius in the target means that more balls will hit . Point of order this assumption is incorrect . I wish I could draw this out to explain . I have no idea if your numbers are correct but lets assume they are . This means that a given Firestorm projectile can hit anywhere within a 25 unit radius . Further , lets assume that the point of impact is randomly chosen from within this circle . This means that if a Firestorm projectile hits on the very edge of that radius , at distance 25 , half of its explosion splash 12 will fall outside of original drop radius . The splash will catch a monster 25 12 37 units away and will only reach 12 units inside the dropradius circle . Since the monster is presumably at radius 0 , this means that the splash misses by 25 12 13 units . So to calculate the chances of a given projectile to hit a monster at the center of the cast radius lets make a couple assumptions . First , to establish the worstcase scenario lets assume the monster ' s hitbox is a single point a larger hitbox will of course be easier to hit . Second , lets continue to assume that the impact point of a firestorm projectile is randomly chosen and there is no special weighting going on . So this means the total area available for the projectile to hit ispi r 2 3 . 14 25 25 1962 However , in order for the splash to catch our zerowidth hitbox monster at the center of the radius it must land within 12 units this gives us the actual target circle . pi r 2 3 . 14 12 12 452 And since we ' re assuming a true random distribution of impact points , we can just divide to find the chance of a single projectile hitting a singlepoint monster 452 1962 23 % Which means at 202 damage per ball and 20 ballssec fallin ' from the sky , on average 20 . 23 4 . 6 balls will hit per second for a damage of 4 . 6 202 929 dmgsec , average . So yes , well below flame surge . However the math changes quite a bit the larger the target ' s hitbox is that 23 % might rise to 50 %, leading to a more favorable outcome . We could run some better figures here if we knew the average side of a monster ' s hitbox , but I don ' t know that so who knows .