Life is a Dream was written at a time when the concept of honor was very important in European societies, especially in the author's native Spain. Social rules were much more rigid than they are today, with everyone in society expected to behave in a certain way according to their gender and social status.
Even so, such rules placed a more onerous burden on some members of society than others. Women, for instance, were expected to come up to exceptionally high standards of chasteness and constancy imposed on them by men. Yet even if a woman did somehow manage to maintain such standards, she could still find her honor and reputation ruined through no fault of her own, but because she had been wronged by a man.
Such is the fate of Rosaura in Life is a Dream. While living in her native Russia, she was seduced and abandoned by Astolfo, the Duke of Muscovy. By modern-day standards, Astolfo has behaved in an unspeakable manner, treating Rosaura as if she were little more than a worthless piece of trash to be discarded.
And yet, by the standards of the time, it is Rosaura's reputation that has been ruined, not Astolfo's. She's the one who has to take drastic steps to restore her honor. It's notable that in order to do this, Rosaura has to disguise herself as a man. As a woman in a rigidly patriarchal society, she has no choice. It's either that or spend the rest of her life locked away in a convent.
Once Rosaura reveals that she is a woman, she is placed in a weakened position. She has to try and convince men such as Clotaldo and Segismundo to kill Astolfo to restore her lost honor and reputation. The irony here isn't hard to spot. Rosaura's honor and reputation were cruelly taken away from her by a man, but she can only get them back with the assistance of other men.
In the end, Rosaura's honor and reputation are indeed restored, and by nonviolent means. But it's rather telling that this only comes about because a man, Segismundo, orders Astolfo to do the right thing and marry Rosaura. And so, at the end of the play, we're left with the abiding impression that honor and reputation in the society depicted on stage are entirely within the gift of men, as indeed is every woman's fate.