Line of effect tells you whether an effect, such as an explosion,
can reach a particular target. A line of effect is a straight,
unblocked path that indicates what an ability, effect, or spell
can affect. A solid barrier cancels line of effect. Fog, darkness,
and other factors that limit normal sight don’t block
line of effect.
You must have line of effect to any target that you cast
a spell on or to any space in which you wish to create an
effect. You must have line of effect to the point of origin of
any spell you cast, such as the center of a fireball. A burst,
cone, cylinder, or emanation spell affects only an area,
creatures, or objects to which it has line of effect from its
origin—a spherical burst’s center point, a cone-shaped
burst’s starting point, a cylinder’s circle, or an emanation’s
point of origin.
An otherwise solid barrier with a hole of at least 1 square
foot through it doesn’t block a spell’s line of effect. Such an
opening means that the 5-foot length of wall containing the
hole is no longer considered a barrier for the purpose of a
spell’s line of effect.

Dissolvi magie, che si può usare nell'uno o nell'altro modo, segue le stesse regole degli altri incantesimi.

Dispel Magic
Abjuration
Level: Brd 3, Clr 3, Drd 4, Magic 3, Pal 3, Sor/Wiz 3
Components: V, S
Casting Time: 1 standard action
Range: Medium (100 ft. + 10 ft./level)
Target or Area: One spellcaster, creature, or object; or 20-ft.-radius burst
Duration: Instantaneous
Saving Throw: None
Spell Resistance: No

Burst
A burst spell affects whatever it catches in its area, even
including creatures that you can’t see. It can’t affect creatures
that have total cover from its point of origin—its effects
don’t extend around corners. The default shape for a burst is
a sphere, but some burst spells are specifi cally described as
cone-shaped. A burst’s size defi nes how far from the point
of origin the spell’s effect extends.

Ok allora è cosi, la mia domanda era stata posta nn sapendo che gli effetti di abiurazione oltrepassassero anche i muri.

Grazie della delucidazione

A burst spell... can’t affect creatures
that have total cover from its point of origin—its effects
don’t extend around corners.