Adopted openly, a unanimity rule gives each member of a group a veto, and the member who expects to be outvoted keeps the power to block.
Borderline: whether this move is justified depends on the situation, and only the person in it can judge.
An example
When the founder of a family-owned food service distributor stepped back, the longtime head of operations proposed that the new executive council of nine decide major matters unanimously. He argued it would keep the team together through the transition, said plainly that it meant any member could block, and the council adopted it. Two years later the chief financial officer proposed replacing the three regional warehouses with one automated center. Eight members came around over four months. The head of operations raised real concerns in turn, about driver routes, the labor transition, and the vendor's references, and told the finance chief directly that he would not agree to closing the warehouses while he ran operations. Each round the council asked for a revised plan. By the fifth revision the proposal had become partial automation of one existing warehouse, and the council approved that unanimously.
Why it works
Blocking becomes nearly free: one member's "I'm not comfortable yet" stops a decision without an argument, a coalition, or any visible political cost. Proposals get worse, because sponsors must negotiate down to a version nobody objects to, losing every feature any single member dislikes. And moving forward costs more with every seat, since the sponsor has to find and settle each objection, re-secure agreement after each revision, and start over whenever a new concern appears. Unanimity does this damage when it is framed as inclusion or cohesion, the group is varied enough that someone will always object, and no override path exists.
The thinking behind it
Ronald H. Coase Coase's The Problem of Social Cost (1960) argues that who holds rights, and how costly it is to bargain, decides outcomes when bargaining is not free. A unanimity rule gives every member a right to block, so any proposal must be bargained past each of them. Adopting the rule openly is a choice about who holds rights, and the member who expects to be outvoted gains the most from it.
Mancur Olson Olson's The Logic of Collective Action: Public Goods and the Theory of Groups (1965) shows why large groups find it harder to act together than small, concentrated ones. Under unanimity the burden falls entirely on the sponsor, who must organize every member, while a holdout needs only themselves. That asymmetry is why the defense attacks the rule itself before any single proposal comes to the table.
When it fits
Members of a leadership group forming or revising its decision rules, who expect to be outnumbered on matters they care about and want a veto. It suits a group where cohesion matters, members trust each other, and decisions that split the group would do more harm than delay.
How to use it well
Propose the rule when the group is setting itself up, before any contested decision is on the table.
- Argue for it on cohesion and shared ownership, which are real benefits.
- Make the veto explicit: say that any member can block, and that you expect to use it rarely.
- When you do block, state the objection plainly and what would satisfy you.
- Hold your veto for matters that touch your own responsibilities.
A veto used often gets the rule changed, while one used rarely protects you for years.
What it costs and where it backfires
Every block draws down goodwill, and a group that watches one member stop decisions repeatedly will change the rule, often around you. The company pays for decisions not made. Your objections have to be made in good faith. Once you invent concerns to keep a veto alive, move the goalposts each round so no answer can satisfy you, or threaten colleagues to keep the rule in place, the veto has become obstruction, and the group will treat it that way.
When it is used on you
Contest the decision rule before bringing the proposal: argue for majority, supermajority, or executive override on decisions above a set size, framed as accountability. Ask that any veto be stated on the record with what would resolve it, and point to neighboring bodies that decide by majority.