when should you build a new fortress?

[Edratman]

An additional major factor is what administration values your starting and second castles have. The range for each is substantial, especially considering terrain modifiers for second castles. The data base complied by Edi combined with the manual is the way to go. For example, if you are Caelum, with a starting 30 admin castle, you could plunk down your second castle almost anywhere without driving resources to zero in adjacent provinces. Or if you location allows building of a river fortress or swamp fort, with low admin, you could plop those anywhere also.

The low admin forts are generally cheaper and quicker. You may not be able to get many high resource troops out of it, but it would be a great site for commander building, allowing your capital to be dedicated to building capital only mages and your best troops.

As you can see, I like to build my second fort as soon as possible in a cheap site without regard to choke points or anything else for that matter. The second castle builds alternately commanders and low level mages, as a general rule. I found that I don't like nations that only have one fort build because of this aspect of my playing style.

[Jarkko]

With MA Ulm I think it is *important* to have more forts as fast as possible. Who cares if the capital has fewer resources at use, if you can build a 800 gp fort next to it and recruit an additional smith per turn sooner? More forts = more income and more resources = more smiths (and more knights too).

It is not like early game is too difficult for Ulm ever, is it? But it is so easy to fall behind in the research race as Ulm, and unless you have enough magic to stop the other players, you'll be just a road-bump when you meet another player. Still, it depends on the situation with Ulm too; best is IMO to look for spots with 800 gp forts and start a new one ASAP (as long as it does not mess up the smith producing in the other forts).

With other nations I tend to be much slower with building forts. Usually building first fort in a choke-point and/or something useful to recruit.

[theenemy]

Thanks for all the answers guys. They will be of great help.