The object is to remove the tiles in pairs and clear the board.

----- From Activision -----

Dear Mr. Ashley,

I am writing on behalf of Activision, Inc., the owner and publisher of
Shanghai. It has come to my attention via your web site at
http://www.xdr.com/dash/sdlshanghai.html and
http://www.xdr.com/dash/linux.html that you have created and/or are making
available for general use an unauthorized derivative work of Shanghai.  I am
writing to notify you of certain facts with respect to this unauthorized
product. 

Activision holds or is a licensee of all intellectual property rights
surrounding Shanghai, including without limitation, international trademark
registration in and to the "Shanghai" trademark.  You can obtain
verification of Activision's registered trademark in "Shanghai" for computer
and videogames from the US Patent office by using this URL:
http://trademarks.uspto.gov/access/search-mark.html. Make sure "Registered"
is checked. Type "shanghai" in the box and hit Search. You will find a list
of Shanghai trademarks.  When I checked last, Activision's was #10 on the
list (Reg. Number 1904528).  On the next page you will see that Activision's
"Shanghai" trademark Serial Number is 74-468336, and the trademark was
registered on 7/11/95.  Activision has been publishing the Shanghai line of
games since 1986.  You can see the authorized Shanghai at
http://www.activision.com/games/shanghai.  Shanghai represents an
extraordinary investment of time and effort by Activision. By advertising,
distributing, publicly displaying and allowing others to play the
unauthorized derivative work of Shanghai (regardless of whether you yourself
were involved in the creation of the unauthorized derivative work of
Shanghai), you are violating international law and infringing upon
Activision's valuable rights.

We therefore demand that you immediately:

        (1) Refrain from or cease advertising, distributing, publicly
displaying and allowing others to play Shanghai or any other unauthorized
derivative work of Shanghai;

        (2) Dispose of all materials related to the advertisement,
distribution, public display and allowance of others to play Shanghai or any
other unauthorized derivative work of Shanghai; and

        (3) Provide us with written assurance that you will refrain from or
immediately discontinue, and will not resume at any time in the future the
advertisement, distribution, public display and allowance of others to play
Shanghai or any other unauthorized derivative work of Shanghai.

In the event you wish to resolve this matter amicably, you can reach me by
email at this address or by phone at (310) 255-2218.  If we do not hear from
you within five business days (one calendar week), we will assume that you
have no desire to resolve this matter amicably and will proceed accordingly.

The foregoing is not intended, nor shall any of it be construed as a
complete recitation of the facts and events concerning the above-mentioned
matter, nor shall it be construed as a waiver of any rights, remedies or
claims, legal or equitable, which Activision may have, all of which are
expressly reserved.

Very truly yours,
Thomas A. Sloper
Executive Producer
[email protected]
Activision, Inc.
3100 Ocean Park Blvd.
Santa Monica, CA 90405
Fax (310) 255-2141