Truth and lies is a complicated theme in Ibsen's The Wild Duck. For instance, Gina Ekdal is living in a lie because she has never told Hjelmar Ekdal, her husband, that there may be some confusion as to Hedvig's paternity: Hedvig's father could be Hakon Werle or Hjelmar Ekdal. However, Gina is living in a wonderful truth because she adores her daughter and wholeheartedly loves her husband whom she protects with tender care. Gina in truth is happy and her family is happy, as separate individuals and as a unit.

Another example of truth and lies considers Gregars Werle. Gregars knows the truth about Hedvig's doubtful paternity and is determined that freedom and happiness require him to enlighten Hjelmar Ekdal as to the dubious nature of his paternity. Gregars is living in the truth. Yet, Gregars is living in a horrible lie because he believes everyone will glad to have the truth come out to dispel what he believes must be an oppressive burden of lies. His life of lies ruins the happiness of the family and causes Hedvig to take her life.

What is the conflict between truth and falsehood in "The Wild Duck"?

In "The Wild Duck," truth and falsehoods clash in many ways and at many times. 

This is foregrounded (and foreshadowed) by the first line of the play: "   Is it true, what folks say, that they're -- very good friends, eh?" Jensen asks if something is true, but in doing so, he uses a euphemism. This lets us know that one of the clashes is going to be between the truth (as in, the facts) and the public face society puts on things.

On the level of plot and character, the truth is often a secret, and there are drives to expose it. Those who want to expose the truth think of ignorance or silence as a lie. Think of how Gregers wants Hjalmar to know the truth about Gina. That's a good example.

On the other hand, Hjalmar knows that fabrication functions as a "life-lie." Not facing the truth allows him to live, telling us truth is dangerous, even deadly.