Source: http://win.wizkids.com/bb/viewtopic....4492172aee8606

I have a character on the rim of elevation level 2 making a range attack targeting another character who is also on the rim of elevation level 2. Between them is just all level 1 terrain with a Great Size character on level 1. Would line of fire be blocked?

WK: No. When drawing a line of fire from one elevation to another (whether different or the same), any characters (regardless of size) or terrain on an elevation lower than the lowest elevation that has a line of fire being drawn to/from it will not affect the line of fire.

In the provided example, since the lowest elevation being used for line of fire is elevation 2, any characters or terrain on elevation 1 will not affect the line of fire.

I have a similar scenario above, but my characters are on an Indoor map and instead of a Great Size character, I have a square of blocking terrain on level 1. Would line of fire be blocked?

WK: No, for the same reason as provided above.