What you're seeing
A shared resource (think: a fishery, forest, or pasture) that regenerates naturally. Yellow dots are harvesters, each taking what seems like a reasonable amount. The field's color shows resource health — green is abundant, brown is depleted.
How to read the graph
The background color shifts from green (healthy) to brown (depleted) as the resource shrinks. The bar at the bottom shows the exact resource level (green → yellow → red). Green particles represent resource abundance. If the resource drops below 1%, the commons collapses permanently.
The key lesson
Every harvester is acting rationally — taking their fair share. But the collective result can be total destruction. No one wanted this outcome, yet everyone caused it. This is why fisheries collapse, why shared pastures are overgrazed, and why shared resources need governance, quotas, or cultural norms to survive.