If you direct enough plays, you'll eventually choose one that includes violence. It comes up more often than you might think, because people in my line of work use the term to include not only times when one character is actively trying to harm another, but any moment of physical business that may pose a safety risk for the actor: someone falls out of bed, or faints, or trips on an electrical cord and pulls down a lamp, etc. Some plays have obvious fight scenes, like Hamlet or Extremities, while others may only include a single punch or a slap or a moment of struggle. Then there are the "sleeper" shows, especially comedies, that don't seem to need a violence designer until the actors start getting banged up. I
The big question, then is: Do You Need Help to Stage the Violence?