For some of the shorter beams (Halberd, Glaive), if you find just the right angle just at the very border of rooms, you can get an additional room that will highlight in yellow. I often take quite some time to perfect the beam line, and I take much care not to budge the mouse before clicking to set the path. In some angles, however, the highlighted yellow path is not damaging all rooms that were highlighted, but leaves out one room, I think the one that is the beam's tangent in the upper corner.
The yellow highlighting can very easily change if the mouse is moved at all, so I think it is a single pixel or so that makes the difference. And I cannot totally rule out that the mouse moved a pixel due to clicking, but the missed room happens a bit too often for accidental shifts in my opinion.
I play in windowed mode at a resolution of 1280x768, just in case the beam path finding algorithm is affected by resolution.
Anyone else noticed this discrepancy in highlighted beam path and rooms taking actual damage? If not, then I guess it's my hand shaking in anticipation of all the wonderful damage after all
