Barabas is an intensely theatrical and endlessly fascinating figure. He is full of contradictory qualities: greed, arrogance, spite, ingenuity, and guile. His resourcefulness is impressive, as he continually dreams up fresh schemes. On the other hand, Barabas's temperament and actions lie at the border between "policy" and lunacy, and some of his behavior suggests the profile of a paranoid criminal.
Abigail is the moral center of gravity in the play. Despite her imperfections, she is able to stand up against her father's evil and to assert her sense of responsibility and integrity. Her death, at her father's murderous hands, marks the structural climax of the drama.
For much of the play, Ferneze is the target of Barabas's revenge. The Jew achieves the first stage of retribution against the governor by arranging for the death of Ferneze's son Lodowick at the hands of Lodowick's rival Mathias.
Lodowick, like his rival Mathias, is portrayed as impulsive and not particularly circumspect. Barabas finds it relatively easy to dupe him and to trick him into a fatal duel with Mathias.
Mathias is Abigail's favored suitor, and her affection for him means that his death in a duel marks a key point in her character development. Like Lodowick, Mathias is hotheaded and an easy mark for Barabas's wiles.
As a character, Ithamore is somewhat indebted to the clever slaves in ancient Roman comedy, such as Pseudolus in Plautus's play of the same name. His loyalty to his master Barabas is skin-deep, since he turns out to be a thief, a hypocrite, and a blackmailer.