- Mana barrier spells don't "block" spells from being cast through them, they act as "Boosted Defense" against spells being cast through them (on the plane they were cast).
Mana barriers page 161 first sentence:
Mana barriers are magical walls that impede or block magic and astral forms.
And for the physical plane version
Mana barriers on the physical plane are invisible (except to astral perception), but they act as solid barriers to spells, manifesting entities, dual-natured entities, spirits, and active foci.
Reads to me that in either version, the Mana Barrier spell impedes or blocks Mana spells. The Astral version doesn't impede or block Physical spells.
the problem comes with the short hand at end of the Astral Mana Barrier description...
Astral mana barriers are resistant to
astral spells as well as other astral forms, in the
same manner as physical mana barriers.
Neither block spells. Both add either a Defense Pool bonus = to the rating of the barrier, or if no defense test, Oppose Test of Barrier Rating x 2.
Only difference I see is what they apply to. Seems that Mana Spells are affected by Astral Mana Barrier and Physical Spells are affected by Physical Mana Barriers.
Separately, an astrally perceiving mage would slam into an Astral or Physical Mana Barrier, requiring the test to force his way through it, where as if he was not astrally perceiving, he would simply walk on through.
Similarly, a spirit, un-manifested, would need to fight through the barrier (destroy it) or have his magician make the contested challenge allowing the magician to bring along spirits. Alternatively, the spirit could just fly around it, assuming that it wasn't cast in the shape of a closed shape, such as sphere, around the unmanifested spirit.
This brings up an interesting question. Are materialized spirits Dual Natured? If so, then they are also blocked by Astral Mana Barrier when materialized, else, it would require a Physical Mana Barrier to block them from moving through. Trying to find a definitive section of book that states whether spirits are explicitly Dual Natured in 6e.
I do think it is sloppy the way they phrased it at the bottom of Astral Barrier.[/list]