(by pzmaniac)
We have already discussed using the Designated Deployment Hex to give the player a core army that he will start the campaign with. Generally the campaign designer also assumes the player will add to this core army by requisitioning new units throughout the course of the campaign.
By way of review, let's remember that it is really quite simple. Core units will be the ones the player purchases and receives as prototypes, added to the ones that begin the first scenario on a designated deployment hex. Period.
All five of the stock SSI campaigns begin with the player possessing a specific core army. The player may start with a little prestige as well, but not enough to buy more than a unit or two. However, some innovative campaign designers have created campaigns in which the player gets to buy his own core army in total, as the first step in the first turn of the first scenario. This can be an interesting idea, especially if the campaign is not intended to be a strictly historical campaign. The way you do this is to give the player a large sum of prestige to start the first turn of the first scenario.*1 Then the player gets the added fun of "shopping" for his core army -- he can spend his prestige any way he sees fit. This creates a huge range of diversity in the campaign since every player is likely to have a different starting core army, and quite often two different players will have completely different core armies to start the campaign.
If you want to create a campaign like this, there are a couple things to keep in mind. First, you will assign no designated deployment hexes in the first scenario. (They will be unnecessary unless you want the first scenario to be playable as a stand-alone scenario that starts with Player 1 owning some units that would not appear in the campaign version of the scenario.) Rather, you must give the player some regular deployment areas, i.e., Supply Hexes at which he can deploy the units he purchases.
Another thing to keep in mind is Designer Control. Although it sounds like something out of Orwell's "1984", I'm actually referring to the ability to predict what a player's core army will look like at a particular point in the campaign. This is crucial when trying to determine how your campaign's scenarios should look. In general, it is best when the campaign designer maintains some level of control over the player's army throughout the campaign. (If you don't like the word "control", substitute "predictability" in its place.)
It isn't hard to control what the player's core army looks like in the first few scenarios. But as a campaign gets longer, it becomes increasingly more difficult to predict what the player's army will consist of and how powerful and capable it will be. This makes it more difficult to create scenarios that are of the proper difficulty level. If you underestimate the average player's core army going into "Scenario X", you might create a scenario that is too easy for the player. By the same token, if you overestimate the player's core army, you will make a scenario that is too difficult; and you even run the risk of creating scenarios that are accidentally impossible to win!
This brings up an important aside. Everyone wants to make at least some challenging scenarios in their campaign. I've never met the designer who WANTS the player to be able to cruise through his campaign without any difficulty whatsoever. A campaign like that is unlikely ever to be played again -- at least by that player. Every designer wants his campaign to have at least a little more replayability than that. But, in trying to create difficult or challenging scenarios, it is often easy to simply be lazy. A GOOD challenging scenario doesn't simply consist of a mass of super-strong, super-advanced, super-experienced enemy units which keeps all but the most powerful, advanced, and experienced core armies from succeeding. A good scenario (regardless of the difficulty level) will make the player want to play it again and again.
Creating a difficult, but do-able scenario can actually be much more difficult than playing a difficult scenario. You must use your head when making such a scenario. Many critics of poorly designed difficult scenarios use the cliché description "fifty airplanes arriving on Turn One" to describe the stereotypical "hard" campaign scenario. Surely there is a time and a place for "fifty airplanes" to indeed "arrive on Turn One." But many aspiring campaign makers resort to this modus operandi time after time. There's no way a player's core army will be able to adequately cope with such a huge horde of enemy planes all arriving at once, therefore the designer thinks he's created a difficult scenario. Well, it's true. He has indeed created a difficult scenario, but not a very original one. Neither is it a scenario which is likely to be replayed.
Ideally, a challenging scenario will end in a loss the first time (or perhaps the first several times!) it is played. But after receiving the loss, a good scenario will still beckon the player to try again. Sometimes a scenario can be so artfully created that the average player will come away shaking his head wondering how such a small OpFor was able to defeat his core army. He will be dumbfounded as to how he could have possibly lost that scenario. Other times there will be a trick -- the scenario will be more like a puzzle that has one specific solution which is not readily apparent, but can be figured out with some thought or replaying of the scenario.
Still other times (though hopefully rarely!) the player will come away absolutely astounded that anyone could be expected to win that scenario. In this case, perhaps you intend that only the most experienced, most innovative, and most stubborn players will ever find a way to win that scenario. If so, you probably should not force other players to lose the entire campaign based upon that one loss. You must remember that if the player does not come away from the campaign with positive thoughts, he won't return to it, nor will he recommend it to others. That won't do either of you any good. The player will be discouraged and will have a sour taste in his mouth from the experience, and you will have lost at least one person who would potentially enjoy the campaign that is the fruits of your labor.
This brings us back to Designer Control. If you, as the designer, have created a campaign in which it is nearly impossible to predict what the player's core army will consist of at a specific point, it is nearly impossible to create a GOOD scenario for that campaign. Once you have lost control of the player's core army, you have to do a lot of guess-work. That means you will inevitably have some scenarios that are too easy and some that are too hard. If you're lucky you'll get a few that are just right. But in most cases, you will end up with scenarios that are BOTH too easy for some players AND too hard for other players. Normally this is not good because it limits your ability to accurately playtest the campaign when checking for difficulty and for replayability.
So when you are making your campaign, it is a good idea to always have a feel for what the typical player's core army will look like before, during, and after each scenario. You should know how much prestige is available for each scenario. This is easy to keep track of, but takes some discipline on your part. Simply add up the prestige you have given to the player. As the campaign's designer you have all the information you need to come up with an accurate total...
First add up all the flags. At 100% prestige, the small flags will be worth 40 prestige, a large flag with a yellow (VH) or green (SH) border will be worth 80 prestige each, and a large half-green/half-yellow bordered flag (a combination VH/SH) is worth 160 prestige. Remember that the player will not get any prestige for the flags that start out as his own flag, and he gets no prestige for retaking flags the A.I. captures. After you have added up all the flags, be sure to add in the prestige that is available each turn, as well as the prestige available at the beginning and end of each scenario.
Yes, there is some uncertainty in these numbers. You have to use your own judgement to determine how many of the flags an average player will be capable of taking and holding. Similarly, you have to remember that a player who ends the scenario early will miss out on some turn prestige, and one who plays until the last turn for a Tactical Victory will get every last penny. In the same way, you must keep in mind the scenario awards you assigned to each type of scenario-ending result. Do all players get the same prestige after the scenario? Or did you assign more or less prestige to certain types of victory or loss? You will probably have to come up with at least two sets of numbers: a high and a low. You should determine the largest amount of prestige a player could possibly have at this stage in the campaign, as well as the minimum amount a player could have.
You cannot control or even accurately assess how much of that prestige will be used during the scenario on taking replacements. And sometimes you will have difficulty estimating how much prestige will be lost when core units are destroyed. You will have practically no control over the prototypes which might be received after Brilliant Victories. But if you diligently keep track of the numbers that you as the designer DO have control over, you should have a good basis of knowledge upon which to rely. And that knowledge should help you create better scenarios with scenarios that have more appropriate difficulty levels.
This brings us to the last point. Whether you give the player a core army with which he will start Turn 1 of the first scenario or you give him prestige with which to purchase his own core army, there is a very important principle you must keep in mind at all times. Although the units that are given to the player from beginning of the campaign will be indistinguishable from those purchased by the player during the campaign, the game treats them a bit differently in regards to the prestige cap (a.k.a. "Jensen Cap).
At the end of each scenario, the prestige value (price) of those units which have been purchased by the player will be added together with any prestige the player currently has. If that amount exceeds the Prestige Cap value for the next scenario, the excess prestige will be deducted from the prestige award the player would ordinarily receive for completing the current scenario.
Units that were originally given to the player at the beginning of the first turn of the first scenario of the campaign do not count toward this total. Therefore, when it comes time to determine the value being assigned to the "Prestige Cap" for each scenario, the designer must take into consideration not only the size of the typical player's current core army, but the designer must also remember that those units which were given to the player at the outset of the campaign do not count toward the player's total core army value.
So, if you give the player a sum of prestige to start the campaign, instead of giving him a starting core army, you must remember that the player's entire core army (aside from prototypes received) will count toward his Jensen Cap*
In summary...
When designing scenarios for your campaign, it is very helpful to have a running total of the amount of prestige that has been given to the player throughout the campaign, as well as a rough idea of what his core army will consist of and look like. Although this will not always be an accurate reflection of the player's actual core army, it will at least help you judge how easy or hard your next scenario should be. Your own good judgement, playing experience, and simple creativity will also be key ingredients. But if you have the cold, hard facts to work with, you will be better able to judge exactly where your creativity should lead you.
Some additional comments by PzManiac
*1 – Please note that this sum has to be given as Starting Prestige and not as Turn Prestige. If you give it out as Turn prestige to be had on game turn 1, the prestige will be affected by the prestige slider, so that anyone playing the campaign at 25% will only have 25% of this amount, which can make it impossibile to play the campaign at lower prestige settings.
*2 The controlling the core is not as easy as Whoopy makes it out here
. It’s one of those things that most campaign designers struggle with. AND it is in fact much easier to control the core if you don’t assign a core army, since then you will be able to control the core more easily (only prototypes will remain as unknown factors). In addition you will also be able to easier compensate player losses by using the prestige and the Jensen cap (With the cap you can ensure that ONLY players having a low core army value will receive the after-scenario prestige necessary to buy replacements)
If you on the other hand assign a big core army, you will have to limit after-scenario prestige a LOT in order to control the core.. In addition you will have other problems with the campaign.. A big fixed core army with not much after-scenario prestige will NOT make the campaign fun to replay, since no matter how many times you play the campaign, it will probably play the same.. So basically IMO a big fixed core army is really NOT a good way to make a campaign attractive. In some cases (when you make a historical campaign for instance) it can be justified of course, but be aware that if you assign a big fixed core it will probably make players less prone to replay the campaign.
This one is also by me... (pzmaniac)
players won’t bother about staying below the cap, so giving out very low amounts it’s really questionable (unless of course you’re making a campaign with an extremely limited time-frame, Jorge’s Stalingrad campaign comes into mind).. On the other hand if you gives out larger amounts of after-scenario (you should however avoid to give out HUGE amounts since this will make the campaign play the same at different prestige levels, something which you of course wouldn’t want 
the player will strive to hold his core size below the cap in order to constantly maximize his prestige earnings.
and other “tricks”.