Click

Standard selection method; selects a single object only

Option-click (Mac) or Ctrl-click (Windows)

Creates a copy of the object and places it directly over the selected object, unless the preference has been disabled (see Vectorworks Preferences: Edit Tab)

Shift-click

Selects multiple objects as each object is clicked; also can be used to deselect one or more objects without affecting other selected objects

Option-drag (Mac) or Ctrl-drag (Windows)

Places a copy of the object where the mouse button is released; a plus sign displays beside the cursor to indicate a duplicate is being made

Rectangle, lasso, polygon marquee

Selects all objects that are completely contained within the marquee

Shift-marquee

Reverses the selection status of objects inside a marquee; if objects inside the marquee are selected, this method deselects those objects

Option-marquee (Mac) or Alt-marquee (Windows)

Selects all objects that the marquee passes through, as well as those contained within the marquee

Invert Selection command

(on the Edit menu)

Deselects everything that is currently selected, and selects all visible objects in editable layers and classes that are not currently selected

Double-click

Reactivates the working plane on which a planar object was created; may also have other behavior such as symbol editing or polygon reshaping, depending on selected settings

Select Vertex in Object Info Palette

(context menu command)

For vertex-based objects, selects a single vertex for editing from the Object Info palette; see Editing Vertex-Based Objects

Force Select 

(context menu command)

Activates the object’s class, layer, or both (as necessary) and selects the object, even if the object could not normally be selected due to a different layer scale, or the current class or layer option settings