In Sid Meier's Civilization series, all computer-controlled leaders have a certain personality associated with them--with variables for things like emphasis on economy, cooperation, backstabbing tendency, etc. In the original Sid Meier's Civilization, Gandhi was meant by the devs to be the most peaceful leader. Gandhi was, in fact, the only leader whose aggression variable was set to 0.

This wouldn't have been a problem, except that in order to mirror real-world historical developments, the dev team decided that once a civilization adopted democracy as its government, the value for its aggression variable should tick down by 1. For every other civilization, this worked fine, but in Gandhi's case setting aggression to -1 resulted in a variable underflow, causing it to reset to the highest possible value.

Adopting democracy usually happens to coincide with advancement into the Modern Era. That, in turn, usually happens to coincide with the attainment of nuclear capabilities, so this happened a lot:

Peace-loving, non-violent resistance leader Mohandas K. Gandhi becomes the first leader to threaten you with nuclear annihilation.

The devs found this bug so funny that they deliberately encoded it into the next four games.