And why not a campaign that would always be on a single map? The campaign would be a "big" mission with lots of little missions, the more you advance, harder become the missions. Then you lose .. nothing. You're always on the same map. And to avoid the supreme commander syndrom (before each new mission you stock the best army possible then trigger the next plot) you can put a time limit to succeed a mission, and if it fails then you have another mission that would take into account that you failed.

For instance you start and you first mission is to know more about some kind of weird dragon. You search its lair but the beast has already been killed by another player. then you can't complete and you recieve another way to achieve you goal : more information on it (with, for instance, you research go only on thaht particular thing for 5 turns).

What about keeping persistence between missions by allowing the opponent to keep their research (with a bonus to keep them evenish with the player) and the like and giving them an army based on the size of the player's force, but smaller and more advanced? For example, in the first mission, the best accessible metal to the player on the section of the map they can access is copper, so their army will be large, but armed only with copper gear with only copper working researched, while the computer also has tin, allowing bronze armed troops to counterbalance the player's superior size. A few deposits will be near the border, allowing a successful attack to jumpstart the player. This draws a fair bit on Sammual's second idea, but limits the tech progression through irrelevance, because the player has no need for any technology past a certain level because the resources to use that technology simply don't exist. This may feel a bit artificial, but will be much less so than a hard limit.

Xthetenth - I like the idea of the mission progressing in terms of resources.  If you took this a step further and made access to the resource a requirement for researching the tech needed to use it you would not have to artificialy limit the players research.

Sammual

First, regarding the concept of campaign continuity in general, I think it's a very good idea. I also think, given that Elemental appears to be based on the idea that you, the player, represent a single, persistent character in the world, that it will be absolutely essential never to take away learned spells or technology between missions. How can I, as a single ruler/character, suddenly forget what I just spent weeks learning? I know people who gave up on the GalCiv campaigns for exactly this reason and I think the problem would be even worse in the more personal setting of Elemental.

I'd point out that it wouldn't take much narrative sleight of hand to talk yourself into a more flexible position in terms of taking away units or structures, though: a cutscene showing your previous opponent's attempt at dying revenge by summoning a magic meteor to obliterate half your town or some mission-intro text explaining that some of your troops were lost fighting off a dragon raid between missions would let you ensure that players never begin a mission with too much power.

I, like Ron, like this approach, especially the alternate version. Depending on other game mechanics, it might also be a natural approach to preventing unit hoarding between missions: an omnipresent unit upkeep mechanic (either in terms of food or money) would work to prevent the accumulation of unnecessarily massive armies not only between but also during missions. Of course, that would have rather profound effects on much of the gameplay, so it might be a cure that is worse than the diseas.

- Ash