License for Massively Multiplayer Games?

Ernest Prabhakar prabhaka at
Wed Aug 11 23:49:34 UTC 2004

Hi Rich,

On Aug 11, 2004, at 4:12 PM, Rich Tsao wrote:

> Hi all:
> I apologize in advance if this is not the proper forum for this 
> question.

This is a fair request.

> I am considering to make an Open Source Massively Multiplayer Game.  To
> create a stable service, I need a specific restriction in Open Source
> license I can’t seem to find in any existing templates so far:
> 1.	Modified versions of the source will not be allowed to connect to
> original software (both client and servers).
> The primary reason for this is to prevent harmful individuals from
> programmatic cheating or other negative user experience for the player
> population.

That's perfectly understandable, but I don't think you can put that in 
an Open Source license. Not sure why you'd want to.   Are you really 
saying to don't ever want *anybody* *anywhere* to allow *any* copy of 
original software to be used by modified software?  Wouldn't it make 
more sense to have that as part of the terms of service for your 

The only thing I can think of that might come close is to require that 
the connection protocol advertise its name and version, and set your 
original software to only allow that connection.  But, I'm not sure 
even that would conform to the OSD.

> Additionally, I would like the following standard restrictions applied:
> 1.	Source-code modifications can only be distributed in the form
> of "patch files" with the source code for the purpose of modifying the
> program at build time.

I'm not sure if that sort of distribution restriction is OSD-conformant 
-- anyone else?

> 2.	Derived works must carry a different name from the original 
> software.
> 3.	No-endorsement clause. Users of the software are barred from using
> the name of the organization or contributors to endorse or promote 
> products.
> 4.	Has explicit patent grant.
> 5.	Contains patent mutual-termination clause.
> 6.	NOT copy left.

> The closest version I found is possibly Open Software License, but it 
> has
> copy left, which I don’t want.  Are there any other Open Source 
> license with
> the above restrictions I am looking for?  If not, what Open Source 
> license
> comes close to these requirements?

Well, I believe the Academic Free license is supposed to be the OSL 
minus copyleft, so you should perhaps start there.  You should probably 
also look at SISSL:

> Lastly, if I were to use GarageGames’ Torque game engine, and it has a
> commercial license.  Is it possible to create a MMOG game that uses 
> that
> commercial game engine and still be Open Source?

At some level, Open Source is really about the various licenses, not 
about the software per se.  The answer depends on exactly what you want 
to do, and probably which license you use.

Good luck,
- Ernie P.

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