“Et tu, Brute?” asks Julius Caesar in the titular play by Shakespeare. “Are you not entertained!?” roars Russell Crowe’s character to the crowd after slaying his opponent in Ridley Scott’s “Gladiator.

In order to illustrate this point, the encyclopedia notably uses an artist’s rendering from Sega’s video game Rome II: Total War, which not only falsely depicts the Pantheon beside the Colosseum, but ...