Boards must exercise the Duties of:
Care - do due diligence, be prepared, make thoughtful decisions in line with our mission and values
Obedience - support the organization and work to reach the goals voted on by the Board (even if you were a dissenter)
Loyalty - prioritize the wellbing of the organization over any other associations or self-interests
There is a bit more to it than that, but that is a quick description. You can review these duties in the ACBS Chapter Board Handbook here. For more thorough, but readable, articles about them please read below.
See more about these duties here:
https://www.boardeffect.com/blog/fiduciary-responsibilities-nonprofit-board-directors/
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