The formal use of Irony in literature and plays has a long history, and as such its usage has altered somewhat over time. In this section the following types of literary irony are discussed:
In essence, Socratic irony is the feigning of ignorance in order to gain advantage from it (for example, playing the fool). The terms itself comes from the philosopher Socrates (thus "Socratic" Irony) who would pose questions and conundrums from an apparent position of innocence and ignorance in order to provoke his audience. It is very much a type of disguise put on by someone who will pretend not to know the subject at hand. Socractic Irony was employed not specifically to amuse, but certainly those around who are aware that the ignorance is false, would certainly find it humorous to see others engaging in lost causes. Socrates himself used this form of irony to peaceably discuss matters, often philosophical, not to embarrass his opponents but to promote a deeper and unbiased level of understanding.
A recent use of Socratic Irony can be seen in the work of actor and comedian Sacha Baron Cohen.
The other most common form of irony is almost certainly dramatic irony and this is discussed here.