The description for splash weapons says:
A hit deals direct hit damage to the target, and splash damage to all creatures within 5 feet of the target.
Does that mean that it hits a 3×3 area, or a plus sign? Are diagonals included? I know for the purposes of movement, moving diagonally once only counts as five feet.
Best Answer
Yes, you include the diagonals, because the diagonals are within five feet.
When calculating distance along diagonals, one uses a “5, 10” alternating scheme: the first diagonal square is within 5 feet (and therefore within the splash), the second diagonal square is 10 feet beyond that (i.e. 15 feet), so it would not be within a 10-ft. splash, e.g. stink bomb.
The section on Throwing a Splash Weapon has more details.