Black Dianetics is a form of Dianetics, as discussed by its creator, L. Ron Hubbard.
Hubbard claimed that Dianetics is a method of achieving set goals using one's mind. According to the Church of Scientology, Dianetics can be used to change and improve one's life. Claims from Scientologists support the idea that Dianetics is a positive concept that can be used to improve an individual's life. However, Hubbard also referred to something he called "Black Dianetics", for which the goals may be mean-spirited, cruel, or exploitative. That is, Black Dianetics employs the methods of Hubbard's ideas for selfish, vindictive, and destructive reasons.
Hubbard warns against the use of Black Dianetics in his 1982 book Dianetics and Scientology Technical Dictionary (ISBN 0884040372). It is also mentioned in Hubbard's famous Philadelphia Doctorate Course lectures, as well in other material.