Final answer:
Flexibility is the quality of an effective plan that allows it to be adapted as situations change. It is essential to have plans that are not rigid so that they can remain effective and relevant over time, even when faced with new challenges or information.
Step-by-step explanation:
The quality of an effective plan that allows for alterations if the situation changes is flexibility. An effective plan must be able to adapt to new circumstances and information. This is akin to setting career goals that are open to adaptation as you learn and grow, or making decisions in a game that might change based upon the dynamic situation of the game itself.
For instance, being flexible about career plans means that you remain open to new ideas and are willing to adjust your original plan as new information comes your way. This ensures that the strategy stays relevant and effective even as external conditions evolve. In contrast, a rigid plan that doesn't allow for change could quickly become obsolete in the face of new challenges or opportunities.