Warner Brothers has been sued by the sole surviving relative of JRR Tolkien, the author of The Lord of the Rings Trilogy, for breaching a contract and overstepping their rights regarding the merchandising of property and allowing characters of her father’s books and films to feature in online gambling games.

Priscilla Anne Reuel Tolkien together with a group of British publishers filed an $80 million lawsuit in U.S. District Court in Las Vegas on Monday claiming that Warner Bros., its New Line subsidiary and Rings/Hobbit rights holder Saul Zaentz Co. infringed the famous books’ copyright and breached a contract that was signed in 1969. It is claimed that a decades-old rights agreement only entitles the studio to create “tangible” merchandise that is based on the books and not as an online slot machine that the estate finds offensive.

The lawsuit against Lord of the Rings slots was triggered after one of Tolkien’s daughter’s lawyers received promotional information via e-mail inviting her to play Lord of the Rings slot at one of the online sites.

Warner Brothers signed a contract with Isle of Man based online casino software provider, Microgaming in February 2010 in terms of which it would create a game based on the top movie franchise.

The Lord of the Ring: Fellowship of the Ring Slot game was thereafter released to online casinos that are powered by Microgaming and has, since its launch, attracted large numbers of slot players to these sites.

Over 150 million copies of the Lord of the Rings trilogy have been sold and it is known to be the third best selling novel ever written.