The humble Arrow Tool received an upgrade in ArchiCAD 13 with the addition of the Direction Dependant selection mode. This means Left to Right will select Entire Elements in the crossing window, Right to Left does Partial Elements.
Did you know that you can use polygon shaped, or angled selection boxes? Just click in the Info Box, and change the Geometry method.
You can change Selection Methods in ArchiCAD by clicking and holding the mouse button on the first icon in your Info Box. The first option(Partial Element) will select any element that has any part inside the selection box you draw. The second option(Entire Element) will only select elements that are entirely enveloped in your selection