I have been asked to explain my Civ2 theory of interest by fellow GOTMer, AliArdavan. It is really just basic RL interest theory applied to Civ2, but it seems many players don't know about it. For simplicity, I will leave out most of the math unless people want to see that. Also (all modesty aside) I have been pretty successful with this in playing over 15 GOTMs, and I am pretty sure many strong players (eg SlowThinker) accept interest theory as common sense. Here are some of the main points: 1) Obviously, it is better to get a free city (from a hut, for example) in 4000BC than in 2000AD, because a city can be used to make more cities. Likewise, a free unit, an extra 100g, whatever - they are all better in 4000BC. Thus, the "present value" of almost any item is greater than its "future value". Based mainly on experience, I estimate typical values "go down" about 5% per turn in most Civ2 situations. For example, if you hoard 1000g for 10 turns, instead of investing it, you just lost about 500g. This principle applies to temples and defensive units sitting idly in your cities - they are costing you! (of course they may also serve a valuable purpose, but you don't want to overdo them). 2) The 5% estimate applies pretty well to settlers/cities too. You should be able to double the size of your civ approx every 14 turns (math omitted - but it's related to the 5%), assuming no major wars/etc get in the way. Eg, 1 city in 4000BC becomes 2 cities in 3300BC, 4 cities in 2600BC etc until you decide to level off. This assumes you invest in growth and not armies, etc. 3) If you get paid 1 gold per turn, for example from the taxes of a small city, you are getting an "annuity". At 5% interest, it is worth the same as 20g (math omitted again) paid in advance. This "x20" factor is important in many Civ2 investment decisions. Example: You have a city making 10 shields per turn and want to build a factory there. The factory will increase production by 5s/t, which is an annuity worth 5x20 = 100s. However, the factory costs you 200s. Bad deal! And I didn't even add in the 4g per turn cost, which is worth 4x20 = 80g up front. I would not build a factory in a city unless it's making about 24s/t (or can do so in the very near future). And I almost never have such cities (see point 4 below). Example: The KRC wonder costs 300s, which doesn't make sense in a city of size less than 15 (15x20=300). You can evaluate Adam Smith and the Colossus in much the same way. 4) If you can find a way to get more than 5% back per turn (eg thru trade bonuses) then DO IT! If you cannot do better than 5%, invest in growth (eg settlers), which usually returns about 5%.