https://burningman.org/event/preparation/first-timers-guide/
This is a good place to start if you want to see why I thought Burning Man when I read “free for all anarchist society”
Isolate them with no food and see what happens next.
lol I thought it was in the desert. I'm saying introduce actual scarcity so people have to start deciding between altruism and personal survival. You'll get a few "criminals", then...
Obviously if you put people in a situation where they have no food or water they are going to start fighting. Law enforcement or anarchy doesn’t matter. Survival can become savage.
Not necessarily starvation level famine, just enough scarcity that there are winners and losers in food production which means inequality. You'll have a government in no time.