Unwritten Rules Are the Most Powerful Force in Boardrooms

What doesn't get written down ends up running the show.

I’ve been in a lot of boardrooms that describe themselves the same way:

“We’re actually a pretty healthy board.”“Everyone cares.”“There’s no real conflict.”

And yet—people are tired. Attendance is uneven. Staff feel whiplash. Decisions either take forever or happen in side conversations.

What’s fascinating is that everyone usually agrees on the mission. That’s not the issue. The issue is that the board is running on unwritten rules.

Unwritten rules are efficient… until they aren’t. They work best for the people who’ve been around the longest. They confuse new trustees. And they quietly turn goodwill into friction.

Governance research backs this up. Groups like BoardSource have found that the most common source of board–staff tension isn’t personality or competence—it’s unclear roles and decision authority. In other words: who is supposed to do what, and who decides.

Here’s a quick diagnostic I use with boards:

1. Can every trustee clearly explain what is expected of them—without saying “it depends”?

2. Can staff confidently say which decisions belong to the board, which belong to the ED, and which are shared?

3. Do new board members learn how power actually works here—or do they learn by accidentally stepping on landmines?

If the answers are fuzzy, you don’t have a culture problem. You have a documentation problem. High-functioning boards tend to write down a few key things: nothing fancy, nothing legalistic:

• What it actually means to be a trustee here

• Where the line is between governance and operations

• What committees are for (and what they are not)

• What participation looks like in real life, not theory

• How board members engage externally without confusing staff or partners

Isn't this easier than a big giant BOARD HANDBOOK OF BORINGNESS? Don't you feel the relief. When expectations are explicit: Trustees don’t have to guess. Staff aren’t triangulating. Meetings get shorter (this alone should sell it)

There’s also a timing thing people underestimate. Research from groups like Bridgespan Group shows boards are most able to clarify governance norms after leadership transitions, not before. Transitions surface what used to be handled informally. That’s not failure—it’s information.

One rule of thumb I like:

If it affects authority, accountability, or workload—write it down

If it affects style or personality—leave room for judgment.

Most boards don’t need new people.They need fewer assumptions.

Good governance doesn’t make boards rigid.It makes it easier for smart, well-meaning people to do good work together—without guessing.

And honestly, that’s what most trustees are hoping for anyway.

Don't get stuck in the "unwritten board rule sleeper sofa."