A highly banned and controversial substance in the Cosmic Era
One of the strangest weapons deployed by Z'pl'rt the Mad
Admirals, I present to you the future of space warfare! No longer will you need to waste billions of credits on costly space battles, and millions of lives on planetary warfare with hostile cultures. For only a fraction of the cost of a heavy cruiser, I present you with a weapon capable of eliminating an entire solar system. "I present the Star Hammer!"
(A powerful and deviously simple weapon to make space warfare in any sci-fi game forever changed)
At regular intervals, a god takes control of your world's weather. Choose the gods at random each turn of the interval and begin applying their effects subtly. Their power will depend on the strength of those who worship them.
For civilised people, worship of a god actually wanes during that god's month in an effort to reduce their potential destructive effect.