With the plot revolving solely around a jurors' table, Rose examines how the isolated men bring into this locked room their own individual experiences and attitudes and how these factors influence their decisions until they are able to separate themselves from what is in their hearts and make their decisive vote based solely upon the facts of the trial. In addition, this setting places together men who in ordinary circumstances would not come into contact with one another, a factor which strongly contributes to the final decision of the jury as some of their experiences act as positive contributions to their decision-making.
Indeed, it is the interplay of the twelve men, perhaps more than any other circumstance or individual characteristic which determines the outcome of the verdict. Clearly, Juror Eight is the key character, but he alone is not completely responsible for the change in the initial decision of "guilty." Rather, his rational unprejudiced thinking acts as a catalyst to stir up what is behind the other's quick, decisive vote against the defendant. For, his words ignite the angry ones of Juror Three, who harbors resentment against youths,
No. 3 It's the kids. The way they are--you know? They don't listen. I've got a kid.... When he was fifteen, he hit me in the face. He's big, you know. I haven't seen him in three years. Rotten kid! You work your heart out...."
Likewise, Juror Ten responds emotionally,
No. 10 We don't owe him a thing. He got a fair trial, didn't he? You know what that trial cost?....You're not going to tell us that we're supposed to believe him, knowing what he is. I've lived among 'em all my life. You can't believe a word they say. You know that....
When this juror makes these visceral remarks, others, such as Juror Eight react and listen. Later, when Juror Three contends that the defendant did the stabbing because it was "down and in," the way someone would stab a taller man, he is questioned by Juror Eight, "Did you ever stab a man?" Then, Juror Five, who has found it difficult to speak because of his timidity, speaks up,
No. 5 Wait a minute! What's the matter with me? Give me that ....Anyone who's ever used a switch-knife would never have stabbed downward. You don't hand a switch-knife that way. You use it underhanded.
Locked into a room from which they are unable to leave until they reach a decision, and under the powerful influence of the rational Juror Eight who staunchly believes in justice for everyone, "the twelve angry men" begin to truly communicate with one another and become more confident in their own knowledge, casting aside their defences of resentment against youth and racial and class discrimination. Finally, then, they reach the fair decision that there is not enough substantial evidence to convict the defendant of murder.