When we played Civilization, we always dreaded the period of anarchy, the time in the game when you switch your government. (To pick a random example, from monarchy to... communism.) During that time, your nation stagnates, no taxes are collected, no research is generated, everyone is unhappy, and military rules all. This is all in a game.
In real life? Anarchy hasn't exactly worked out either, for obvious reasons. But perhaps its biggest success (to use that word quite loosely) was the Free Territory that existed right after the Russian Revolution.
For a period of three years, a portion of southern Ukraine was
ruled (not the right word...) governed (not the right word...) led by Nestor Makhno, an anarcho-communist military leader. Together with him was Volin, born Vsevolod Eichenbaum, a Russian Jew who made a large contribution to the theory of anarchism. Volin's big idea was to create some kind of super anarchism that would combine aspects of its various branches.
Volin was arrested in 1920. By the next year, the Free Territory was no more, taken over by the Red Army. Volin actually lucked out, as he ended up in France and lived until the 1940s. Makhno was exiled as well... and everything has been hunky-dory in Ukraine ever since.
Real life is a tad more complex than Civilization...