In the play, the coin flip represents the possibility of human life. That is, life is a gamble with very bad adds. It describes meaningless of life. Also, there are existentialism and absurdity in the play. For example, complexity among the dialogues.
The coin in the play symbolizes the power of mortality, which makes human life and free will meaningless. Fifty percent of the money comes in coins or rounds, but in the game it constantly comes in rounds, which means that death is always inevitable. We can say that absurdity of life also.
The play is an absurd comedy and this play involves death, fate, reality and existentialism themes. Stoppard uses an absurd approach to highlight the absurd and irrational situations faced by characters.
Also, Stoppard's play focuses on Rosencrantz and Guildenstern secondary characters in "Hamlet" providing an absurd and comedic take on their experiences and existential questions.