暴雪原话:
oskills work differently for classes that "own" that skill
This is all intentional, in order to balance these
items.
Skill Points that work for Any Class
("oskill" Skill Points) The Trang-Oul's Avatar Set gives
+18 to Fireball and +13 to Fire Wall. The boost to fireball
(as well as Frostwind's arctic blast bonus and a whole lot of
other items) are examples of what's internally known as an
"oskill". These are skill bonuses that work for any class. If
a Necromancer is wearing a Trang-Oul set, he'll get +18
fireball and any +X To All Skills equipment can further
increase this. The same applies to all other non-sorceress
class wearing a part of that set.
However, oskills
work differently for classes that "own" that skill. In this
case, it's a Sorceress getting a bonus to Fireball. In the
other case, it was a Druid getting a bonus to Arctic Blast. If
a character gets an oskill bonus to a skill that class "owns,"
the bonus is restricted to a maximum of +3. If a Barbarian is
dual-wielding Call to Arms runeword weapons, the +3 cap is
applied to the total from both weapons. This is all
intentional, in order to balance these items.