@Whelkman
Really? No red shirts in higher governments? I've never made an empire big enough to test. It would take at least 28 cities in Monarchy/Communism, but those governments are stupid, so it'd really take at least 37. Obviously that's a quaint little civ to you.
@JEELEN
Discussions about what's a cheat and what's not never get anywhere, so I'll just be a pedant and point out that a programming error is a bug regardless of whether it can be exploited to the player's advantage.
At first I thought zero-turn revolutions might be good for:
1. Saving a little time during the single grand switch to representative government you make in a game.
2. Disregarding the senate.
Now that I've thought about it more, there's potentially a far more powerful use:
3. Get Pyramids and switch to Democracy any time you need to deliver a caravan to maximize the bonus, then switch right back to avoid happiness problems. (Be sure to rearrange your workers too! Caravan bonuses are based on projected arrows, so you can starve your people for the caravan, and switch right back before the turn ends.)
And one I just thought of:
4. Zero-turn from Democracy to Democracy every other turn so you can overthrow the government before your people get around to it (only with Pyramids of course).
Suddenly this tactic looks so powerful I might call it a cheat too.
@Henrik MN
On Chieftain, the enemies never declare war. It's like having Great Wall or United Nations the whole game (which makes it more foolish than normal to build them). On Emperor, once an enemy finds you, it'll send a barrage of units and fortify them next to your cities. Later, as described in
the link Whelkman gave, peace means nothing and they'll sneak attack you at every opportunity.