Continuity mistake: After Lucius kills the wild monkey, he's got blood all over his mouth, beard, chin, and neck. When he stands up, he's spotless.
Continuity mistake: When Macrinus is poisoning Caracalla's mind, telling him about supposed plans of his brother to use him as a scapegoat, Caracalla shouts, "That's a LIE, he's... he always LIES." The cup suddenly switched hands.
Continuity mistake: Glyceo grabs the sword on the arena floor and extends his right arm. An instant cut later, his arm is lowered, then it cuts back to the previous angle of his arm extended.
Continuity mistake: When Lucius asks the doctor to give him the prison keys and send a message to the soldiers at Ostia, Lucius' arm is bent around the prison bars, except for a brief shot where it's suddenly straight; then the shot changes and it's bent again.
Continuity mistake: After the Virgil quote scene and the fight that follows, Lucius takes a bath. There's a close-up of him saying something about dying in the arena, and his hair is suddenly better brushed and drier. Then it goes back to the previous wet hairstyle.
Continuity mistake: When Lucius fights against Macrinus, Macrinus kicks some sand and blinds Lucius, who covers his face. An instant later, his hand is on the floor.
Continuity mistake: When Lucius addresses both armies at the city entry, he throws his sword on the floor ahead of him. He walks around, and from the opposite front angle, one can see the sword behind him. From the immediate opposite angle of his back, the sword is gone.
Continuity mistake: After Lucius quotes Virgil, he kills a man who collapses on a chair. When he lies dead, there's a leg or armrest on the floor parallel to his body. A shot later, it's perpendicular.
Continuity mistake: When Lucius steps in the water to see his wife's corpse, his hairstyle around the forehead changes between shots before he is splashed by water.
Continuity mistake: During the riots night in Rome, Macrinus and Caracalla talk to Geta, his monkey on his shoulder. The position of the monkey is inconsistent in every single shot.
