How you plot hidden lines in AutoCAD depends upon whether you are plotting from model space or paper space. Plotting from paper space is recommended.

Plotting Hidden Lines From Paper Space

To plot hidden lines in paper space, you need to tell the viewport you are plotting to hide the entities in it before plotting them.

1. Type MVIEW at the command line.
2. Type S for shadeplot.
3. Type H for hidden
4. Select the viewport.

This setting will be saved with the drawing.

Plotting Hidden Lines From Model Space

To plot hidden lines in model space, you need to set the Shade plot setting to Legacy hidden.

1. Type PLOT at the command line.
2. Expand the Plot – Model dialog box so that the Shaded viewport options are visible. Do this by pressing the arrow in the bottom right of the dialog box, as shown below.
   
3. Set Shade plot to Legacy hidden.
   

This setting will be saved with the drawing.

If you plot from the command line, you need to select a detailed plot configuration. One of the prompts will be Enter shade plot setting. Answer Legacy hidden to that prompt to plot with hidden lines.