Things not to do in Civilization III: detonate 270 ICBMs in one turn, blasting every other civilization back into the stone age (or at least to cities of size 3 or below).
Why shouldn’t you do this? Because the resulting global warming took fifteen minutes to resolve. That’s fifteen minutes each turn, for the rest of the game. Fortunately, there were only a few turns left, as my Modern Armor rolled across the countryside razing cities. Then I signed peace treaties with the survivors.
Belatedly, it occurred to me that this is the sort of behavior that the folks in Berkeley and Hollywood are expecting from the current administration.