Does a Barrier created a ground level, block LOF between elevated characters?
ExxxxxBxxxxxE
ExxxxxBxxxxxE

E is elevated
B is Barrier
x is grounded terrain

Who is General Barrier?

If all the terrain is Indoor...yes, If its all Outdoor...no.

Barrier markers are blocking terrain and follows the rules for blocking terrain. Outdoor blocking terrain on a lower elevation does not affect line of fire from elevated to elevated terrain.

but does it block from elevated to grounded?

Blocking terrain on the same elevation level as either the target or the attacker will block line of fire.

So in your example, a clear line of fire between the two targets on the elevated terrain exists. But however if either one of them was on the ground, where the barrier exists, then the line of fire would be blocked. Quebbster's post (#6) sums it up pretty well

LOL :speechles Actually this post helps a ton, I was never quite sure what barrier could do in certain situations

I think Barrier is the MOST underused, underestimated power out there.

Agree. (filler)