What are the similarities and differences between theater and circus in ancient Rome?

In ancient Rome, slaves and punished free citizens were recruited into the theater as actors as punishment. Theatrical performances were staged three times a year. It was a kind of competition between playwrights. Three playwrights presented three performances and one satirical play. Masks were rarely used by actors, only to enhance the voice. The actors were treated with disdain, they could even be beaten.

The circus in ancient Rome was different from the modern one. Mostly in the circus, horse rides were arranged.