What is the primary legal effect of a landmark decision?

The primary legal effect of a landmark decision is that it changes existing legal interpretations. Landmark decisions often arise from cases that are so significant that they reshape the understanding of certain laws or the Constitution itself. They set new precedents that lower courts are then required to follow, which can lead to profound alterations in how laws are applied and understood.

For example, a landmark ruling may redefine the rights of individuals or the authority of governmental bodies, thus influencing future legal cases and rulings. This reinterpretation can have a ripple effect throughout the legal system, as other courts adjust their stances to align with the new precedent established.

In contrast, while reinforcing existing laws or creating new regulations might be outcomes of other decisions, these actions are not the primary effects of a landmark case. Additionally, while a landmark decision might result in the nullification of previous decisions, such an outcome is not always the case; what defines it as landmark is its ability to change legal interpretations rather than merely cancel past rulings.