They're the same thing.

The elements that some claim distinguish OBEs from Lucid Dreams are, in reality, just variations of dreaming.

As most lucid dreamers will tell you Dreams are very much driven by expectations.

Everything from absence of body, to ghostly hands or silver ropes anchoring you to your body are simply dream elements.

There is absolutely nothing that OBEers can give as evidence which can't simply be explained as being part of the dream.

Heres the hilarious part. Say you have a False Awakening and find yourself in your bedroom. Then oops, you notice an extra window - OBEers will claim thats ok, your room just looks a bit different on the Astral Plane.

Say you have a near perfect repreduction of your flat, and surprisingly find you can use your astral body to move a book around.
Guess what, when you wake up the book hasn't moved.
What do the OBEers say. You guessed it - the Astral Plane get out card.