Spoilers are pieces of information that reveal key plot points or twists in movies, books, or TV shows, often ruining the surprise for those who haven't experienced the story yet. For example, if someone tells you that Darth Vader is Luke Skywalker's father before you watch Star Wars, it can take away the excitement of discovering that moment on your own. Many people try to avoid spoilers to fully enjoy the unfolding of a story. This is why some fans will say "no spoilers, please!" when discussing popular series like Game of Thrones or Harry Potter. Spoilers can lead to heated debates about whether they enhance or detract from the experience.