In Manhattan court papers, Take-Two Interactive Software and subsidiary Rockstar Games call the case frivolous and maintain it was "filed for publicity purposes".
They are seeking to have the case dismissed and the 28-year-old Mean Girls star pay their legal fees.
The actress sued in July over Grand Theft Auto V. Her suit says the game uses her image, voice and style and evokes her via a character named Lacey Jonas.
But Take-Two says her voice, name and likeness are not used and the character resembles her only in being a young, blonde woman.
Rockstar Games have a base in Edinburgh where the game was developed.