Clean room reverse engineering

Chris Travers chris at
Fri Dec 4 23:22:37 UTC 2009

On Fri, Dec 4, 2009 at 2:13 PM, David Woolley
<forums at> wrote:
> Marc Whipple wrote:
>> In any event, the concept of “reverse engineering” copyrighted material is
>> nonsensical under US law (and the law of many other countries.) If you had
>> enough access to it to reverse engineer it, you didn’t make a new work, you
>> copied an old one. If your new work otherwise is
> IANAL, but as I understand it there is a limited right to  do white box
> reverse engineering in the EEC.  It is a lot more limited than is generally
> assumed in open source circles, and would not extend to reproducing internal
> behaviours.
> As I understand it, the key points are:
> - it must only be to the minimum degree necessary to interface with the
> software;
> - the author of the software must have refused to provide that information
> on reasonable terms;
> - the knowledge you gain cannot be published.

IANAL, but I think Marc is talking about something else.

In US copyright law, I understand that reverse engineering is
generally allowed provided that expressive elements of the code are
not included.  Expressive elements could be anything from variable
names and comments to organization of the source code.  Typically this
is accomplished by having one team reverse engineer the code and
provide a report of functional components to another team who then
writes replacement code.

The problem is that, although this process works fine on a functional
level for games, the storyline characters, concept, etc. are also
artistic, expressive elements.  So while one could, say, clone the
Doom engine without too much trouble, cloning the Doom game would pose
additional problems which are substantial.

(Now, I suppose if you are reverse engineering The World's Best Chess
Game, this might not apply, but I assume this is not what we are
talking about here.)

Also this might be different in other countries.

Best Wishes
Chris Travers

More information about the License-discuss mailing list