ZombieRoboNinja
First Post
It would increase the average damage to 32 if it was rerolls 1s. (1d6 reroll 1 is equivalent to 1d5+1, average 4). But the feat doesn't do that, it merely flips a rerolled 1 to a 2. Thus the die distribution is {2,2,3,4,5,6}, which averages out to 11/3, or 3.67, a 1/6 increase on average. So an 8d6 fireball now does 29.33 on average.
Yeah, basically the reroll adds almost nothing to your average damage and is almost never actually relevant. It's kind of like an even worse version of the Great Weapon fighting style. I guess it's there so that this feat "feels" more useful when you're not facing resistant creatures, without actually BEING more useful (which might make it feel like a "feat tax"), but I'd rather they not insult our intelligence and either just leave it out or add a simple +1 to damage or something and save us extra rolls.