The biggest irony in "The Bet" involves with the fact that the lawyer makes a bet whereby he could win a fortune if he can remain in solitary confinement for fifteen years, and then when the fifteen years is almost up he renounces the money because of what he has learned during his confinement. He was enduring his imprisonment for money, and then forfeits the money with only five hours left to go. It would appear that he has gotten something more valuable out of fifteen years of solitude, meditation, writing, and study than two million rubles. He leaves a note for the banker explaining why he is forfeiting the bet at the last moment.
"You have lost your reason and taken the wrong path. You have taken lies for truth, and hideousness for beauty....To prove to you in action how I despise all that you live by, I renounce the two million of which I once dreamed as paradise and which I now despise. To deprive myself of the right to the money I shall go out from here five hours before the time fixed, and so break the compact..."
For many years he studied the works of the world's greatest thinkers, including the teachings of the New Testament. He must have become convinced that money and material things can be a hindrance to spiritual and intellectual growth. In this respect he resembles other famous men besides Jesus. These include Buddha, Mahatma Gandhi, Socrates, and Thoreau, to name only a few.
Another irony is that while the lawyer has been progressing intellectually over the fifteen years, the banker has been deteriorating financially and morally. He is an unhappy man. At one time the two million rubles he was wagering meant little to him. He tells the lawyer:
"To me two million is a trifle, but you are losing three or four of the best years of your life. I say three or four, because you won't stay longer."
Now that fifteen years have passed, however, the two million the banker stands to lose by noon the next day mean everything. If he has to pay the money he will be bankrupt, and in the meantime he has grown old.
"Cursed bet!" muttered the old man, clutching his head in despair.
Not only has he lost the rest of his millions by "wild speculation," but he has deteriorated morally to such an extent that he is actually planning to commit murder to get out of having to pay the money the prisoner has rightfully won. Moreover, the banker has sunk so low that he is planning to have someone else blamed for the crime and probably sent to Siberia for life.
"If I had the pluck to carry out my intention," thought the old man, "suspicion would fall first upon the watchman."
It might be considered ironic that the man the banker has been keeping imprisoned for fifteen years is described as "a lawyer." If the banker simply refused to pay the money, he would not only be disgraced in the eyes of all the important men who saw him make the bet, but he could be subject to a lawsuit for two million rubles by a man who had legal training and who has been doing nothing but studying books for fifteen years.
When the banker has read the prisoner's note renouncing the money,
...he laid the page on the table, kissed the strange man on the head, and went out of the lodge, weeping. At no other time, even when he had lost heavily on the Stock Exchange, had he felt so great a contempt for himself.