Dramatic Irony

Dramatic irony is that situation where the audience watching a play are fully aware what is happening on stage and in the story at any given moment, whereas and whilst the characters themselves appear to be totally unaware of what is happening to them.

There is another feature about dramatic irony. Many of the plots of Ancient Greek plays were based on well-known myths and legends, many of which would have been well-known to the contemporary audiences then. They, the public, all knew what was going to happen next. The use of a well-known myth or story meant that the audience was always in anticipation of the downfall of the principal character in the case of a tragedy as the play progressed. Dramatic Irony could work both ways.  Of course the playwright could change the plot of the myth or legend if he so wanted thereby creating a surprise for his audience who were expecting some other outcome, or they could have their ironic expectation satisfied.

Irony as a Dramatic Tool

Irony, particularly dramatic irony, is a cornerstone of Sophocles' Oedipus Rex. The audience is privy to information that the characters are not, creating a sense of foreboding and tension. This discrepancy between knowledge creates a powerful dramatic effect.

Dramatic Irony: The audience knows Oedipus is the murderer they seek, while he remains oblivious. This knowledge intensifies the dramatic impact of his investigation.

Situational Irony: Oedipus flees Corinth to avoid fulfilling a prophecy, only to inadvertently to fulfil it. This ironic twist highlights the futility of his attempts to control fate.

Verbal Irony: Oedipus mocks Tiresias for his blindness, ironically highlighting his own spiritual blindness.

References

Philip Vellacott (12 June 1975). Ironic Drama: A Study of Euripides' Method and Meaning. CUP Archive. ISBN 978-0-521-09896-0.

Helene P. Foley (15 March 2019). Ritual Irony: Poetry and Sacrifice in Euripides. Cornell University Press. ISBN 978-1-5017-4063-3.
Ritual Irony - Poetry and Sacrifice in Euripides - Internet Archive

Robert L. Perkins (2001). The Concept of Irony. Martin Antic: Clouds of Irony: Mercer University Press. pp. 161–. ISBN 978-0-86554-742-1.

On the pretense theory of irony. [PDF]

Some Aspects of Dramatic Irony in Sophoclean Tragedy
S. K. Johnson
The Classical Review
Vol. 42, No. 6 (Dec., 1928), pp. 209-214
Published by: Cambridge University Press on behalf of The Classical Association
https://www.jstor.org/stable/701419

Philological Museum vol 2/On the Irony of Sophocles - Wikisource