Warning: may get too mathematical for some (although a mathematician would laugh at that statement, I'm sure).

Many Civ III players use temporary cities to try and get the most benefit from their empires (a technique often referred to as 'Ralphing' around here). This is an attempt to derive some criteria for when camps help, and when they should be disbanded to improve the overall production of the empire. Much use is made of the corruption formula, deduced mostly by Alexman. If you aren't familiar with the two types of corruption (OCN and distance) then you'll probably want to read that to make sense of this.

The basic criteria here is that the time to abandon temporary cities is when the loss in production due to abandoning those cities is exceeded by the increase in production due to reduced corruption in the rest of your cities. Cities further away from your capital (or FP) than the cities being abandoned decrease corruption by an amount that depends

If

e T = U n / (2 N)

If we define

A > U / (2 N e)

So once you have claimed as much territory as you can, without going to war (i.e. you've run up against AI borders or coastline in all directions), and you want to know if it is worth putting down some camps, what you have to do is:

The number calculated gives you the average number of tiles each camp has to work before you are gaining a net benefit from the presence of the camps. If this number is less than 2, building camps will be of immediate benefit (a size 1 camp works 2 tiles). If it is larger than two, you'll have to do some kind of estimate of how long it takes the camp to grow large enough to be a benefit. For example, suppose you have 8 size 6 cities outside your intended camp placements, giving

One of the (perhaps) surprising features of this is that as long as it is advantageous to add camps, it is advantageous to add as many as possible. There is no optimum number of camps. And once the number of camps you have becomes more of a hindrance than a help, the the best number to have is zero - get rid of them all. To judge when to get rid of camps, you use the inequality above. Generally, your camps stop growing, but you continue to add outer cities (and improvements to cities you already have) until

Improvements are a consideration here. Courthouses (and WLTKD) are an obvious factor that changes the effective OCN for a single city. If all your cities have courthouses, the effective OCN is raised by 25% (which actually makes the camps

I've ignored the problem of having cities that are 95% corrupt, and which won't get any benefit from disbanding camps. I'm assuming that the camps lose usefulness some time before you get that many cities, so it should never be an issue unless you've kept your camps for far, far too long.

One last issue to address is the resources used to make camps. Obviously, they use up one settler. Plus, before they produce any units, they need to build a barracks. That is a cost of 70 shields (50 for a militaristic civ) and one population point (two used to make a settler, making a size one city). The population point is quickly recouped, by virtue of having a new city that is growing. So as long as your camps hang around long enough to produce 70 shields worth of units, they represent a net benefit in shields, and as long as they produce at least 1 gpt to cover the barracks upkeep, they are pure profit in the science/tax department. So most of the time, the cost of building a camp is quickly overtaken by the production from that camp.

As a rough guideline, on a standard map, regent level, camps in a ring around the capital remain useful until the number of tiles being worked by permanent cities outside the camps exceeds the tiles worked by the camps by a factor of 6-8 (7-9 for courthouses) depending on government type. So 4 size 3 camps (working 16 tiles) will be useful until you have about 112 tiles being worked by cities beyond those camps (in a republic, ignoring courthouses).

The same principles apply for those who prefer building camps beyond the first ring of permanent cities - you just need to worry about the cities beyond the camps, and the corruption in the camps themselves. The cities further in have no effect on this.

Is it worth posting a table of OCN for various map sizes and difficulty levels?

Many Civ III players use temporary cities to try and get the most benefit from their empires (a technique often referred to as 'Ralphing' around here). This is an attempt to derive some criteria for when camps help, and when they should be disbanded to improve the overall production of the empire. Much use is made of the corruption formula, deduced mostly by Alexman. If you aren't familiar with the two types of corruption (OCN and distance) then you'll probably want to read that to make sense of this.

The basic criteria here is that the time to abandon temporary cities is when the loss in production due to abandoning those cities is exceeded by the increase in production due to reduced corruption in the rest of your cities. Cities further away from your capital (or FP) than the cities being abandoned decrease corruption by an amount that depends

**only**on the number of temporary cities being abandoned, and is the same for all cities (assuming that all camps being abandoned are at the same distance from the capital - on the other hand, if you have in order of distance capital-camp-city-camp-city then the first city gains the benefit of having one camp disbanded while the second city gains the benefit of having both camps disbanded). So the total increase in productivity for these cities depends on the number of camps disbanded and the total number of tiles worked by the further out cities. The production you lose depends on the number of tiles worked by the camps, and the total corruption in those camps.If

*n*is the number of camps being disbanded,*T*is the number of tiles worked by camps that are being disbanded,*C*is the total fractional corruption in those camps (between 0 and 1),*e=1-C*is the efficiency (also between 0 and 1; 0 efficiency is 100% corruption, 1 efficiency is 0% corruption),*U*is the total number of tiles worked by cities that are further away from the palace/FP than the camps, and*N*is the modified optimal city number for the map size, difficulty level and other OCN modifiers, then the break even point (where the presence or absence of camps makes no difference) is:e T = U n / (2 N)

If we define

*A=T/n*as the**average**size of the camps, then the criteria for camps to be beneficial is:A > U / (2 N e)

So once you have claimed as much territory as you can, without going to war (i.e. you've run up against AI borders or coastline in all directions), and you want to know if it is worth putting down some camps, what you have to do is:

- Decide where you want your camps to go
- Count how many tiles are used by cities further out from the palace than the camps
*U*(don't forget the city square: number of tiles is total population points plus number of cities) - Calculate the corruption (and therefore efficiency
*e*) each camp would have (this requires you to either know how to do this from the corruption formula, or be satisfied with a rough guess) - Know what the effective OCN
*N*is - Calculate
*U / (2 N e)*

The number calculated gives you the average number of tiles each camp has to work before you are gaining a net benefit from the presence of the camps. If this number is less than 2, building camps will be of immediate benefit (a size 1 camp works 2 tiles). If it is larger than two, you'll have to do some kind of estimate of how long it takes the camp to grow large enough to be a benefit. For example, suppose you have 8 size 6 cities outside your intended camp placements, giving

*U=56*. Suppose you are playing deity, on a normal sized map, and are a non-commercial civ, in despotism. Then*N=11.2*. And you are placing your camps 3 tiles from the capital, with no cities closer in, giving*e=0.863*if the camps are connected to the road network. Then*U / (2 N e) = 2.90*, so size 1 camps are going to reduce the efficieny of your empire. But if they grow in 10 turns (while the size 6 cities mostly can't grow, for the sake of argument), then in 10 turns time the camps will be of net benefit, and will be of increasing benefit as they continue to grow.One of the (perhaps) surprising features of this is that as long as it is advantageous to add camps, it is advantageous to add as many as possible. There is no optimum number of camps. And once the number of camps you have becomes more of a hindrance than a help, the the best number to have is zero - get rid of them all. To judge when to get rid of camps, you use the inequality above. Generally, your camps stop growing, but you continue to add outer cities (and improvements to cities you already have) until

*U / (2 N e) > A*, at which point it is time to get rid of those camps (or, once you see that point approaching, start turning those camps into workers).Improvements are a consideration here. Courthouses (and WLTKD) are an obvious factor that changes the effective OCN for a single city. If all your cities have courthouses, the effective OCN is raised by 25% (which actually makes the camps

*more*desirable, since their effect (and hence the benefit of getting rid of them) is reduced). Libraries and marketplaces also have an effect - due to the increase in science and gold, they increase the effective number of tiles worked - a city with a university and bank gets double the benefit for each tile, so the number of tiles it is working is effectively doubled, although the number of shields it is producing isn't affected. Obviously, judging the effects of such improvements is not an exact science (although it can be done exactly), but with some kind of estimate of the number of improvements you have, it is possible to get a rough correction to*U*to judge when the camps have outlived their usefulness.I've ignored the problem of having cities that are 95% corrupt, and which won't get any benefit from disbanding camps. I'm assuming that the camps lose usefulness some time before you get that many cities, so it should never be an issue unless you've kept your camps for far, far too long.

One last issue to address is the resources used to make camps. Obviously, they use up one settler. Plus, before they produce any units, they need to build a barracks. That is a cost of 70 shields (50 for a militaristic civ) and one population point (two used to make a settler, making a size one city). The population point is quickly recouped, by virtue of having a new city that is growing. So as long as your camps hang around long enough to produce 70 shields worth of units, they represent a net benefit in shields, and as long as they produce at least 1 gpt to cover the barracks upkeep, they are pure profit in the science/tax department. So most of the time, the cost of building a camp is quickly overtaken by the production from that camp.

As a rough guideline, on a standard map, regent level, camps in a ring around the capital remain useful until the number of tiles being worked by permanent cities outside the camps exceeds the tiles worked by the camps by a factor of 6-8 (7-9 for courthouses) depending on government type. So 4 size 3 camps (working 16 tiles) will be useful until you have about 112 tiles being worked by cities beyond those camps (in a republic, ignoring courthouses).

The same principles apply for those who prefer building camps beyond the first ring of permanent cities - you just need to worry about the cities beyond the camps, and the corruption in the camps themselves. The cities further in have no effect on this.

Is it worth posting a table of OCN for various map sizes and difficulty levels?

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