[kasnavada]

If the forts stay as useful as they are now, I also agree that no one would upgrade... If the upgraded fort gives special bonuses, maybe ?

I was thinking of this idea : every fort would have the possibility to add an upgrade, that would give special bonuses to it.

Examples of bonuses :
- recruit one type of capitol-only unit (either a commander or a troop),
- reduce magic cost for one school (depending on the background of the race, ie : 10% of forging for ulm ?),
- auto-spawn one (or more) of the race units,
- reduce the cost of one type of units recruitable there (for example, a tower that would reduce markata cost, or minotaur cost),
- increase gold or production from the province,
- act as a second temple,
- something else.

Short of something like this, there is nothing that would make me upgrade... forts are overpriced compared to what they currently offer. Maybe they are meant to be !