Essentially, stichomythia is a technique where alternating lines, or half-lines, are given to alternating characters, voices, or entities. The term originated in the literature of Ancient Greece. Passages of stichomythia generally occur during moments of high tension or conflict between characters. Another way (which I seem to prefer) of defining stichomythia is as a dialogue consisting of short lines spoken by alternate speakers. Generally, the speakers (usually two), would be doing one of the following:
- insulting each other
- arguing with each other
- engaging in a contest of wits (a contest of wits meaning individuals with opposing aims who compete with each other using their intelligence, as opposed to their force).
In terms of the use of stichomythia within Shakespeare's Richard III, consider Act 1, Scene 2, where a verbal sparring between Richard and Lady Anne occurs:
RICHARD: Lady, you know no rules of charity,
Which renders good for bad, blessings for curses.
ANNE: Villain, thou know’st not law of God nor man.
No beast so fierce but knows some touch of pity
I hope this helps!