Civilization – How long does it take to play civilization to the end

From my experience, 3 military is good enough for average defense, it allows you to hold out till you can reinforce.

But for your style of play, perhaps 5-10 would be better, you don't want to many as it causes slow down in tech etc..., but then you don't want to get crushed. You should have more on the outer cities and reinforce from your inner ones, I try to always have 3 minimum in all cities, but doesn't always work, then any bigger cities up it to 4-5.

If you notice your enemies normally attack you with massive stacks, the only way to counter those are with a large stack yourself. Have 1 large stack that walks between cities and does the attacking, then leave 3 units in all your cities for normal defense, remember if you suddenly get attacked at a choke point (hopefully you have one) you can always reinforce from your other cities, knocking them down to 1-2 stuff like that.

Whenever you finish a game (either winning or losing/retired, does not matter), you will be able to see a quick replay of the whole game on a symbolic, strategic map, showing land, cities and borders. The finished game report shows some various, concise bits of information about each Civilization achievements, such as founded cities, completed wonders, captured/razed cities or attracted great people. Each finished game is then placed in Hall of Fame, and you can see such replay of every game placed there.

As far as I know, there is no way to record game as a whole, including technologies invented, civics chosen, units produced etc., as in Starcraft or Warcraft 3 - this could be problematic, since games in Civilization usually consume quite a few hours (I completed a few that took a dozen or more hours - in single player of course). This might have changed in one of Civ4 expansions - just note that I played only the original version.