They do take ages to work out, but are worthwhile. As a quick crib:
Fantasy: There are three special events, I think. Getting Ally with Dwarves - to do this, get a skald to bribe a dwarf. You've probably seen them wondering around the place, lokking like barbarians, and wondered what they are doing there. The first time you do this, you will discover the Dwarven king, who will give you the secret of Ally with Dwarves.
Getting Ally with Frost Giants. This one seems to be quite random - suddenly one civ (possibly yours) will get the ability. I haven't discovered the trigger, but it's only happened to me twice. You can still bribe individual frost giants to join you -they are quite powerful. If it's another civ that gets this, you have to steal it off them - I couldn't get the swine to trade it with me.
Dragon Lord - to get this, a dragon has to be defeated, by another civ. You'll probably have noticed the occasional dragon flying around the place. If you kill it, nothig happens, but if another civ does (probably only by accident or at higher levels) then they get dragon lore and a lot of money. You then have to steal dragon lore and get researching the subsequent techs to start producing dragons. When you can do that, the upper two worlds are yours.
It can be bloomin' annoying waiting for the last two events to happen, but fun when they do.
Sci-fi: Again, three events. I can't remember what the techs are, but basically, you need to kill one example of each of the wierd (and extrememly powerful) creatures that appear and generally decimate your army if they get in the way. These are the barbarian units which don't look like units you can produce (intelliraptors, ophions, or whatever). They appear later in the game (I've not noticed if there's a trigger event). When you kill each one, you get a special tech, which is essential to building Earthgate. One type of unit only appears on the gas giant. Each unit is very powerful (20:20 +) so can take a lot of killing, but later units can do it OK. The hard part is getting them to stay around long enough to be killed - they move very fast.
You've probably noticed that you get a new special tech every time you build the first unit capable of travel to a new world.
Extended version: Once you land on Alpha Centauri, you will start a new tech tree, whcih leads to transendence (?sp) (and incidentally b*ggers up some of your wonders like Mike's Chapel, so watch out!)
Hope this all makes sense, and helps you get the most out of these versions. I find them great fun, and a good change from normal CIV.
