Generally, a heuristic is an approach or method that may not guarantee 100% efficiency or exactness in its results, but can provide a reasonably accurate or close answer within a specific domain of tasks. For instance, in a platformer game, it is not necessary to simulate every aspect of physics. Instead, you can simulate certain parts of physics or create a simplified representation using a predefined table (similar to how it's done in Mario games, if I recall correctly). There are situations where an exact value is not required, and as long as the error remains below a certain threshold, there is no need to be overly concerned.