Shift Modifier icon Shift

Use the Shift action to change what happens to the selection when you Shift+Click an element or hold Shift while drag-selecting. Click the Shift button to switch between the three states: Add, Remove, or Difference.

Same Shift-drag action has different effect depending on Shift setting

From the main menu, select Tools > ProBuilder > Interaction > Toggle Drag Selection Mode.

The button displays the following to indicate what state the action is in:

Icon mode: Text mode: Description:
SHIFT Modifier Add Shift: Add Shift+Click adds the selected elements to the current selection.
SHIFT Modifier Subtract Shift: Subtract Shift+Click removes the selected elements from the current selection.
SHIFT Modifier Difference Shift: Difference Shift+Click toggles the selection: it adds unselected elements and removes selected elements.

This action is available in the vertex, edge, and face modes.