Wells' Theorem is a concept in probability theory that provides a method for calculating the likelihood of certain outcomes in a random process. It is particularly useful in scenarios where events are dependent on one another, allowing for a more accurate assessment of probabilities compared to simpler models. The theorem is often applied in fields such as statistics and game theory, where understanding the relationships between different variables is crucial. By using Wells' Theorem, researchers and analysts can better predict outcomes and make informed decisions based on the calculated probabilities.