A long-festering squabble over Scrabble and an alleged online knockoff spells L-A-W-S-U-I-T.

Hasbro (HAS), which holds the North American rights to Scrabble, has filed a lawsuit in New York Federal Court against RJ Softwares, an Indian software company. RJ Softwares are the makers of Scrabulous, a similar crossword-based game available on Facebook.

Hasbro charges that Scrabulous violates its copyright and trademark for Scrabble. In a separate action, Hasbro asked Facebook to block Scrabulous, but the online social networking site did not immediately do so.

Scrabulous has attracted about 500,000 daily users in the year since Facebook let outside developers post programs that can be added to personal profile pages.

Electronic Arts (ERTS), a video game maker, released the official version of Scrabble for American and Canadian Facebook users last week as part of a licensing deal with Hasbro. But the lawsuit says many Facebook users continue to use the unauthorized Scrabulous.

Hasbro asks the court to order Scrabulous removed from Facebook and to order developers Rajat and Jayant Agarwalla, brothers living in Calcutta, to pay unspecified damages.

Facebook was not named as a defendant in the lawsuit.

Mattel (MAT) holds the rights to Scrabble outside the United States and Canada, but did not join the lawsuit. It has signed a deal with RealNetworks (RNWK) to make a legal online version in other markets.

Earlier this month, Mattel won the battle of the dolls after a federal jury decided that rival Bratz dolls were conceived while their creator worked for Mattel, a verdict that could means millions of dollars in damages for MGA Entertainment, maker of the rival Barbie doll.

File Hasbro’s lawsuit under “copyright law” (serious stuff) and the “lawyers’ full employment act” (annoying stuff).

Or, if you prefer, C-O-N-N-I-P-T-I-O-N.