Stage combat is a specialised technique in theatre designed to create the illusion of physical combat without causing harm to the performers. It is employed in live stage plays as well as operatic and ballet productions. With the advent of cinema and television the term has widened to also include the choreography of filmed fighting sequences, as opposed to the earlier live performances on stage. It is closely related to the practice of stunts and is a common field of study for actors. Several actors famous for their stage fighting skills have backgrounds in dance or martial arts training.