Tragedy of the commons
Etymology
The "commons" was shared grazing land in England. The illustration — herders each adding one more animal until the pasture is destroyed — dates to an 1833 pamphlet and was made famous by the ecologist Garrett Hardin in 1968. The word "tragedy" is used in its dramatic sense: an outcome that unfolds inevitably from the setup.
noun · /TRAJ-uh-dee uv thuh KOM-unz/
When individuals acting in their own interest deplete a shared resource that would benefit everyone if preserved.
What it names
Overfishing, traffic, burnout on a shared team — situations where what’s rational for each person is ruinous for the group.
Example
When everyone grabbed the shared credit and skipped the shared chores, the team hit a tragedy of the commons.
Related idea
It’s a negative externality at scale; a Schelling point or clear rules can sometimes avert it.