Pinter’s style of ambiguity so strong to the point of frustration. In a lot of his plays, he presents dialogues which seem incomprehensible but are largely similar to actual dialogues in real life. For example, in dialogues in your real life, you don’t have the need to elaborate on every detail if a friend of yours is familiar with what you’re talking about. You and your friend may have inside jokes which could be conveyed with uttering a single word and no context is needed. The two of you might make references or tangents without so much as a segue. In some plays, this is what Pinter was experimenting with. In other plays, such as Hamlet, we are given ample historical background and soliloquies during which the characters completely reveal their justifications and motives. Pinter eliminates all of this. His plays tend to be totally isolated; usually confined to one room as if the room is isolated from the past and future. The play just begins. We just get dialogue. It’s as if the audience is walking into the middle of a conversation and wondering what is going on – for the entire play.
Adding to this uncertainty, there are elements of Absurdism, both in the comedic and existential sense. In The Birthday Party, Goldberg and McCann’s dialogue with Stanley goes from intimidation to teasing and in the end it is unclear if they are there to hurt him or to somehow make him better. We, the audience, can only guess their motives and what the outcome might be. All we have is a very odd situation and mostly realistic, occasionally non sequitur dialogue. The whole play fluctuates between playfully strange events and tension rising to uncertainty (i.e., Stanley playing the drum.)
In The Dumb Waiter, we have kind of the same thing; moments of odd comedy spliced with uncomfortable tension. Gus questions things; this infuriates Ben. For Ben, the world is black and white. Or, maybe for Ben the world is only one color because he needs no justifications; he merely carries out his work. Gus questions things repeatedly, including the nature of killing. The play ends, and we speculate that Ben must eliminate Gus; but we can’t be sure. The audience/reader might react like Gus’ character, asking questions and only getting more Absurdity or worse; silence.
What does it all mean? Well, it’s an experiment of dialogue with no context. And it is an allegory of modern life; the uncertainty of truth, unreliability and the modernist theme that the individual must seek closure from the power structures which dictate what he or she does in life, which tends to be counterproductive. The pre-Modern individual would find closure with religion, relationships, art, etc. Not the case with Pinter's characters. (These are generalizations but predominant themes in these periods.)
Ben is an automaton, ready to kill Gus if he is told to by the “powers that be.” Gus is more human, asking questions. More allegory; some questions won’t be answered, because of hierarchies, bureaucracies, or just plain bad communication.