This is a method I read in some article on DMing a year or so ago. Basically, you take any point in your world's history as a starting point and list off the major powers of that period. Then list all the relationships between them.
So let's say I have the Empire, the Free City, and the Rebellion as the major powers at a certain time.
I list
Empire
Free City
Rebellion
then
Empire - Rebellion
Empire - Free City
Free City - Rebellion
For each power and each relationship, roll a 1d100. This will give you a relative sense of how well a power is doing or how good a relationship lies between the two powers. If you know that you want the Empire to be exceptionally powerful at this time in your history, you can arbitrarily give it a score, like 94. Once you have the scores, you explain them the best you can.
So
Empire - 94
Free City - 17
Rebellion - 42
As you can see from this situation, the Free City is having serious troubles, and the Rebellion is not doing terribly well either.
For the relationships
Free City - Empire - 74
Free City - Rebellion - 27
Empire - Rebellion - 92
The first two are easy enough to explain. The Free City perhaps has entered a treaty with the Empire which has Imperial troops on the streets, making it safe from the hated Rebels. This is resulting in secret arrests and essentially mass witch hunts in the Free City.
The last one would usually be very hard to explain as the two are supposed to be enemies. But perhaps the Rebels are being led by someone who is secretly an Imperial. While he pretends to hate the empire, he actually spends most of his time campaigning against the complacent Free City. This gives the Empire an excuse to occupy the city and though the Rebels are able to steal enough food and supplies to keep things growing, they are obviously not accomplishing their goal of overthrowing the Empire, and thus, membership is becoming unstable. While that doesn't put the rebellion on the same low level as the Free City, it certainly explains it's slightly lower than 50 score.
It's an interesting mechanic. I personally prefer simply deciding how the power structures work by what's best for the story, but if you want a random result on how power groups interact, this is certainly a good way.
The system seems to break apart with too many incongruous rolls, however, so it might be best to use it for brainstorming on rare circumstances.
~ElDo
It's a great system for getting those creative juices flowing, or if you ever need to do something on the fly.
By the way, the original article is here. (http://www.roleplayingtips.com/readissue.php?number=272)
I think that it is a good random method. For instance, if you want to throw in the wild card element or challenge yourself. Regardless of how creative you are sometimes things might get a bit too neat, at least I have that problem sometimes.