Proportional Editing
Soft selection that moves nearby geometry
Also known as: Blender proportional editing · Blender soft selection · Blender O key · Blender falloff move
Definition
Proportional editing is a Blender mode in which moving, rotating or scaling a selection also affects nearby geometry, with the effect fading with distance. Press O to toggle it, and scroll the mouse wheel while transforming to change the radius. The falloff, such as Smooth, Sphere or Linear, sets how the influence drops. It is how you pull a soft hill from a flat plane, adjust organic shapes and refine forms without selecting every vertex.
In production
Use a smooth falloff for organic shapes and a sharper one for hard changes, and enable Connected Only so it does not pull in geometry from a different part of the mesh that is close by. If the result is too strong or does nothing, check the radius and falloff. It works in Edit Mode and also on objects in Object Mode, where nearby objects follow the selection.