Since its first performance and publication, Waiting for Godot has been subject to numerous interpretations. In many instances, academics and readers have understood the play allegorically. While some read it as Christian allegory, others read it as a historical allegory. The stark setting, small number of characters, and overall austerity make the play especially apt for symbolic readings.
Given that the name of the long-awaited Godot literally contains the word "god," it isn't difficult to understand why English-speaking readers would understand the play as a Christian allegory. In this reading, Vladimir and Estragon would symbolize people whose purpose is their faith in God. Struggling for salvation, the characters make it through the "muck" of life because they believe the afterlife will be better. Even if Vladimir and Estragon have minimal reason to believe that Godot will arrive in the evening, especially after he doesn't turn up in the first act, they keep waiting for him in the same place. Their blind faith in Godot's future arrival keeps them from going anywhere else, even if they both repeatedly express a desire to leave.
While much lends credence to this reading, Beckett himself cast doubt on the idea that he wrote the play with a clear religious allegory in mind. When he was asked who or what Godot is, he responded, "If I knew, I would have said so in the play." Beckett's response encapsulates the weariness that artists often feel when people ask them to explain their art. It also indicates that he didn't write the play with a one-to-one symbolic system in mind. A work can contain Christian themes, symbols, and allusions without being a Christian allegory. Besides, Beckett originally wrote the play in French—in which there's no correspondence between the name "Godot" and the word for God, dieu.
Other allegorical readings of the play are more historical. Beckett wrote Waiting for Godot in the years after World War II, when the Cold War was ramping up. Some have read Pozzo as a representation of the U.S.S.R., who both abuses and relies on Lucky, the Eastern satellite countries. This Cold War ambience is not difficult to imagine. As soon as the play begins, the apocalyptic barrenness of the setting brings to mind a nuclear landscape. This becomes even more pronounced when Vladimir and Estragon start evoking "all the dead voices" and asking where "all these corpses" and "skeletons" are from. At one point, Vladimir says that "In an instant all will vanish and we’ll be alone once more in the midst of nothingness." When Beckett wrote the play, the bombings of Hiroshima and Nagasaki had taken place just a few years prior. For those who lived through these horrific events, much seemed to vanish in an instant.
Still others have read the play through the frame of psychoanalysis, understanding the various characters as representations of Sigmund Freud's conception of the human personality. According to Freud, the personality is composed of the Id, the Ego, and the Superego. In part because of the resemblance between "Gogo and Didi"—the men's nicknames for each other—and "Ego and Id," some readers have chosen to interpret the characters as components of the Freudian self.
Ultimately, it seems difficult to reduce Godot to a single symbol or Waiting for Godot to one coherent allegory. The elusive, postmodern Beckett was more interested in playing with absurdity, obscurity, and meaninglessness than crafting a perfectly literal allegory. While the characters, setting, and events may function symbolically, the play as a unit does not necessarily have an overarching hidden meaning.