I just tested it again... its 8 yards, not 4 not 10. My lethargy is level 23 - so I get 8 yards. Find a Maggot (not their babies) as they tend not to move. I use a tainted demon who also tend not to move but they do fire fireball but with 1 point in tainted it doesn't do much damage, if cast lethargy with one edge on the maggot and I stand just at the opposite edge with my tainted it will kill the maggot if I cast BB. If i move slightly out, it won't.
This is odd as when I tested it on ptr drop it didn't hit so far away. In any case, happy that its back to 8 yards.
Hephastos it might seem bigger but probably cause the dude is phat....?
Its about 10 yards not 8, but the difference is 8 yard spells like nova and sigil are using collision detection, and that extends the collision size of each target by the size of its tiles, about 1 yard for size 2 actors along their axis. Blood boil and static field and other direct aoe checks only use distance between actors, center to center. So an 8 yard collision spell is kinda like 9 yard aoe spell, and blood boil showed about 1 yard larger than nova when I tested it, which equates to its 10 yard radius when it displayed 20 yard range, as they apparently used diameter.
But for all we know they could nerf it before its live patch and if they do, 2/3/4 yard radius would be unplayably bad and 2/3/4 yard diameter would be so broken blood boil might not even hit targets at melee range, an urdar could be hugging enemies as close as possible after a telestomp and still not be able to boil them