OFFSET — Offset

Creates a parallel copy at a distance.

Creates a parallel copy of an object, at a distance or through a point: parallel lines, concentric circles and arcs or equidistant polylines.

Usage

Type OFFSET (or O) or click Offset on the ribbon.
Give the distance (a number or two points), or press Enter to use the remembered one (variable OFFSETDIST); if you last chose Through, that is the default.

Specify offset distance or [Through/Erase/Layer] <…>:

Select object to offset or [Exit/Undo] <Exit>:

Specify a point on the side where the copy goes (with a distance) or the point it must pass through.

Specify point on side to offset or [Exit/Multiple/Undo] <Exit>:

The prompt of step 3 repeats so you can offset other objects. Press Enter to finish.

Through: the offset passes through the point you give; the distance is measured to the object.
Erase: erases the source object after offsetting it (Yes/No).
Layer: the copies go on the Current layer or on the layer of the Source object.
Multiple: keeps asking for points; each copy is offset from the previous one.
Undo: removes the last offset (and restores the source if it had been erased).

Offsets lines, circles, arcs, polylines, construction lines and rays. In polylines, outside corners are extended until they meet, inside corners are trimmed, arcs that would get a negative radius disappear, and whatever lies closer than the distance to the original (self-crossing polylines) is discarded; the result can be more than one piece.
A circle or arc offset inward by more than its radius cannot be created and a message is shown.
It does not use the previous selection: objects are picked one at a time during the command.
Variables: OFFSETDIST (remembered distance, negative = through) and OFFSETGAPTYPE: how the outside corners of polylines are closed (0 extending the segments, 1 with an arc whose radius is the distance, 2 with a chamfer at the distance from the vertex), as in AutoCAD 2027.
An ellipse or a spline is offset into a spline, as in AutoCAD: it follows the offset curve (within a millionth of the drawing size). Inward beyond its smallest radius of curvature it is not offset.