The audience is meant to sympathize with Gus, the well-meaning, slightly slower junior partner-in-crime to Ben. We are in the same position as Gus: like Gus, we are not familiar with the job they are going to perform, we don't know what exactly is happening upstairs from the basement, and Ben's betrayal should be as much of a shock to us as it is to Gus. Gus is somewhat child-like, pestering Ben with numerous requests, complaints about their environment, and questions. He is generally submissive to Ben's orders—everything from making tea to investigating outside the door—though he stands up for what he believes in, as with the "Light the kettle" argument.
Gus is more sensitive than Ben to issues of traditional human concern. He often touches upon deeper issues Ben does not wish to contemplate—about death, the dull routine of life, and the nature of the elusive employer Wilson. He is concerned with the consequences of his job. He is haunted by the image of their messy murder of their last victim, a girl, and is anxious about this next job. He is fed up with the dull routine of life, but can do nothing to get out of it. His recurring trips to the bathroom underscore his imprisonment to routine, especially in contrast with Ben, who never goes to the bathroom. Unlike Ben, he has no hobbies, which accounts for his awareness of his static life.
If one were to read The Dumb Waiter as an allegory of capitalist slavery, then Gus is the employee who, because life offers him so little, recognizes something wrong with the class structure. He sees cracks in the façade of Wilson—he is unafraid to yell and peer up the serving hatch to where the god-like figure reposes—but still feels uneasy in his presence, as most underlings do with their powerful bosses. He also places accountability on Wilson as the controller of the means of production; although Ben tells him otherwise, Gus believes that Wilson owns the café and should therefore pay for the gas meter (he is also miffed that Wilson, or the person upstairs, wants tea while they are hungry and thirsty). Gus's class-consciousness includes some shame about his poverty, but it is less than that exhibited by Ben. When they send their working-class food up the dumb waiter, Gus calls out the brand names as if announcing a fancy dinner menu. Many productions of The Dumb Waiter will give the actor playing Gus a Cockney accent to emphasize his lower-class standing, but little else is known about his background. We learn that he has not seen his mother in a long time, that he enjoys soccer, and is somewhat unfamiliar with the richer sport of cricket.
By the end of play, Gus becomes somewhat resigned to his life enslaved to routine. He accepts Ben's instructions to kill by mechanically repeating them. When he realizes that Ben is betraying him, his silence does not seem like one of shock. Rather, he has turned into a dumb waiter—manipulated by others to carry out their directions, unable to speak for himself.
Ben is the more dominant of the two criminals. As such, they resemble the various couples in Samuel Beckett's Waiting for Godot, who also complement each other with submissive and dominant traits. Ben broods and reads his newspaper, and his silences are as much a feature of his character as his dialogue. Whether Gus is asking him about the job, Wilson, or if he ever gets bored with life, Ben refuses to enter into a meaningful discussion. Part of the reason, of course, is that he does not want to reveal the purpose of the job: to execute Gus. The other reason is that Ben's chilling silences are laced with a defensive violence. Harold Pinter has defined speech as a strategy designed to cover the nakedness of silence, and Ben is a prime example. He compensates for his naked silences with a constant aura of violence and intimidation. And just as he frequently checks his gun to maintain his potential for violence, his often-venomous speech further obscures his naked vulnerability. In the argument over the phrase "Light the kettle," the marriage of violent speech and violent action seems appropriate when Ben chokes Gus while screaming "THE KETTLE, YOU FOOL!"
Ben's language denotes other parts of his personality, especially his shame over his lower class. He feigns understanding the names of the orders for exotic dishes sent down via the dumb waiter (where upstairs, presumably, someone of higher standing, physically and socially, presides). When they run of food in the basement, he tells Gus (who yells up the hatch) to observe decorum, then strains to make a formal apology. He is also immensely pleased when the person upstairs uses Ben's phrase "Light the kettle." Like Gus, Ben is a slave to the organization (one with several "departments"), but he does not have the same class-consciousness as Gus; his partner is more aware of their unfortunate lot in life, while Ben considers themselves "fortunate" and diverts himself with hobbies. He also accepts whatever Wilson tells him to do, making him as much a manipulated mute carrier of actions as Gus is to Ben—a human "dumb waiter." His betrayal of Gus at Wilson's behest is an unsettling reminder of what workers will do to gain the acceptance of their superiors.
Wilson never appears in the play, but he is directly or indirectly behind the messages from the dumb waiter and speaking tube. His obvious theatrical corollary is Godot in Beckett's Waiting for Godot. Both are off-stage characters who exercise a powerful, god-like influence over the on-stage characters. When Gus suggests that Wilson is playing "games" with the men (the orders for food), it raises the possibility of Wilson's having a sadistic personality—a malevolent god. Not only is he going to execute Gus, for unknown reasons, but he will put him through an agonizing final day. Gus also mentions that Wilson put them through tests several years ago to prove themselves, so we know that Wilson may also be paranoid (a reasonable expectation for the head of a crime syndicate).