What is the significance of this act in terms of plot development?

In a play where not much happens, this act features several encounters that would be immensely significant, were it not for Chekhov’s droll tone and the lack of any consequence or change following said encounters. There is Helen’s attempt to find out Astrov’s feelings for Sonya, Astrov’s attempt to seduce Helen, Serebryakov’s announcement that he wants to sell the estate, and Vanya’s breakdown and subsequent attempted murder of Serebryakov.

All of the characters, critic Kael D. Kramer writes, “are determined to make a melodrama out of something that is ordinary human experience.” They “try to maximize the minimum, creating the effect of anticlimax.