Oblique drawings are designed to show a three dimensional view of an object. The width of the object will still be drawn as a horizontal line, but the depth can be drawn back at any angle. You can choose the best angle to make the drawing look the best. There are three types of obliques, cavalier, normal, and cabinet obliques. Cabinet drawings are when the you cut the depth in half. Cavalier drawings are when you keep the depth the full measurement. Normal drawings are when you cut the depth by 3/4.
The following guide will present to you the ways to create an oblique drawing.
You can use a picture of a Three-View drawing to get the dimensions. Using those dimensions you can make a oblique drawing.
Start with the front view and draw the construction lines that you would see from the front view. These would be light lines that overlap that give you an idea of what the drawing would look like. This is not the actual drawing of the object.
Then draw all the depth lines at an angle back from the front view. Connect all the lines that would be on the top view that you can now see in the oblique.
Now, once you have all the construction lines done, go over and darken the lines that should be the visible lines, the outline of the object. You have to think in 3D to do this. There are not going to be any hidden lines on an oblique drawing.
For a finished example of a oblique drawing (file viewable in AutoCAD LT), you may click the link below: