A few days ago, I came up with an Esbionage Victory condition for GC3 (link @ top of post, for those who are interested). GWSwicord saw it, and apparently took a liking to it, as he thinks it would look good in Elemental. Of course, we know so very little about the esbionage system in Elemental and whether there will even BE one, but assuming that it works like the one in GC2, all you would need to do is achieve the highest possible esbionage level on every surviving empire. Now, if the system worked EXACTLY like GC2's, this would create a large spend+wait-fest, so I have come up with an Elemental esbionage system:

1. Spies are a special type of unit that you can train in your cities. They take a set amount of money to train that increases with each consecutive spy, but that money can be cut by techs and buildings. When you have trained a spy, you can keep training him and adding gear to him just like a regular unit, or give him extra esbionage training that increases his effectiveness. You can then send him out onto the map to get to another city.
2. When the spy is on the map, he can do one of two things. He can strike out over land, at which point he becomes just like a regular unit of yours (no way for the other guy to tell that he's a spy) and behaves the same way, too, but he needs to be trained like a regular soldier to do so. He can also join a caravan, but only if he is carrying no other gear. If the caravan is interrupted and destroyed, you lose the spy.
3. When the caravan reaches the city, the spy enters that city. If the spy comes in overland, he can enter a city covertly, but has a % chance of failing and getting caught. You can decrease this chance the longer you train the spy. When the spy has entered the city, you can assign him to any of the buildings.
4. When you assign a spy to a building, he goes to work in that building. Each type of building has an esbionage type, minimum value, maximum value, and some have a discovery value.

• Type is the type of info you get from the building: research buildings give you info on whatever they are researching, forges give you info on what they are making, et cetera. Buildings like capitals or taverns give you info on everything, as well as stuff you can't get from  the others like race stats.
• Minimum value is the amount of info "points" the spy CAN collect. The actual amount can be higher or lower depending on how oong you trained him. The number also grows slowly the longer he is on the building (exactly how quickly is dependant upon training, again) until it reaches
• the max value. This is as high as you CAN go for that particular building. Now, of course, something like a stable would have a very low value, while a town hall or an empire capital would have a very high value.
• The juicier bouildings (tavenrs, garrisons, castles, etc.) also have an increased risk of capture, as giverned by the capture value.

5.  The spy stores information until you tell him to dump it to you, as opposed to instantly revealing it. If he gets captured, whatever info he had is no longer accessible, unless you resue him by sending another spy into the city.

6. Every time you tell your spy to do something (switch buildings, dump info, leave the city, and so on), he runs the risk of being captured. This risk is increased by the building's natural risk level (see above). A spy could sit for an infinate amount of time on a building with no internal risk and never be caught, but there is a constant, low-level threat of capture if the risk level is above 0.

7. If a spy is captured, you will get a hefty diplo penalty with that empire, but it decreases over time. If you let the spy sit there for X number of turns, he will be executed, and you will (obviously) lose him forever. Except for a "resurrect dead spy" spell.... In any case, before that time, you can send another spy in to resue the one in jail. This carries a bit of risk, as there is a fair chance that one or the other will be killed or (re)captured, or that both will. However, such a resure will dramatically boost your morale.

8. There are human and fallen spies. A human spy can only go to human-contr cities, and vice virsa. Spies of the opposite race are much, much (I was thinking of 2X more) expensive.

9. The info you have from a spy won't go away if you make him leave the city, but it will not update, and your esbionage level will decrease.

10. Lastly, you can build improvements in a city to increase the risk of detection in all of the buildings, or fund police efforts. If you put in too much policing, however, your citizens will start to get ticked.

11. I will probably add some kind of "sabotage" mechanic, but not right now.