The god Hermes changes the course of fate in Greek tales through his roles as a messenger and trickster. His cunning and cleverness allow him to navigate the boundaries between mortals and gods, often influencing events in significant ways. By delivering vital messages or using his wit to deceive, Hermes encapsulates the unpredictable nature of fate. His interactions challenge human understanding of destiny, showcasing that while one may strive for control, the divine often intervenes with unforeseen outcomes, reflecting the complexities of free will.