The characters in Trurls Machine have very different personalities. First, we meet Trurl, the constructor. He is a scientist and an inventor, but he has an artistic side. This he shows by giving the machine face. He has a quick temper and no patience for stupidity. He also is firm in his beliefs as he demonstrates at the end of the story when the machine is trying to get him to give in. Never! roared Trurl, as if he no longer cared what happened, ¦ (Lem). Klapaucius is Trurls friend and rival. He is also a constructor, but a much more light hearted one. He is always looking on the bright side and he never shies away from adventure. He also has a quick wit and is able to put a comical spin on most things. The machine is described by Klapaucius, Not only is it sensitive, dense, and stubborn, but quick to take offense, and believe me, with such an abundance of qualities, there all sorts of things you might do (Lem)! It, like Trurl, is quick to anger.
Lem uses the plot of the story to get his message across. In the beginning, the machine declares that 2+2=7. When it meets resistance in the form of Trurl and Klapaucius, who mock it, the machine becomes angered and escapes its foundations in order to chase its tormentors. Here the tormentors become the oppressed. The machine goes on a rampage; it destroys the town that Klapaucius and Trurl hide in and continues to chase them up the mountain. In its anger, the machine causes too much collateral damage and ends up destroying itself.
There is also much symbolism in this story. The machine is meant to symbolize the communist party. It tries to censor the opinions of Trurl and Klapaucius, mainly, that 2+2=4. Trurl and Klapaucius are the oppressed citizens suffering under the communist regime. They are persecuted for their beliefs. The landslide symbolizes the point at which a population can no longer stand their oppressors and must act. The oppressors go too far and cause their own demise.
Trurls Machine successfully portrays the struggle of oppressed people against those who would censor their beliefs. Lem was able to use character, plot and symbolism to achieve this effect. The story shows that if the oppressed stand up to their oppressors, there is a great chance that they will prevail.