Heuristic bias refers to the tendency of people to rely on mental shortcuts or simplified strategies—known as heuristics—when making judgments or decisions under complexity or uncertainty. These heuristics serve as cognitive shortcuts that allow for efficient information processing and conserve mental effort. However, overreliance on or misapplication of heuristics can lead to systematic deviations in thinking, known as biases. Unlike random errors, these biases are predictable and follow consistent patterns. Common types of heuristic biases include availability bias, representativeness bias, and anchoring effects. They appear widely in domains such as investment decisions, public policy, and everyday judgment, influencing how individuals assess probabilities, values, and risks.