World 7 at the moment is the only world which is being seen by the script as not meeting the qualifications to be ignored.
hmm... I might make an exception in the script to accomodate multiple world closing(s), however I do not want to overly flood the game with additional worlds. Too many worlds can be as much of a problem as too few.
Oh, and yes. game year(s) and length(s) are selected at random. game year(s) are anything between 1950 and 2007 at the moment (i need to establish some kind of fuel costs for 2008 to include this year), provided there is sufficient time to play the full length of the game (i.e. a 10 year round won't start in 2007, but at the latest 1997)
game length is randomly selected with about a 50% chance of being a 5 year round, 40% chance of being a 10 year round, 9% chance of being a quick 1 year round, and 1% chance of selecting anywhere at random between a 1 year and a 25 year round.
Year selected by the script is what drives some of the other things, like which default plane there is, etc. other things are just as random as the above two factors.