It's somewhat random.  If you notice, some techs appear shaded more brown or red.  These techs have a less than 100% chance of being available when you level up in a research field.  The Empire tech tree has more of these than Kingdom, especially in the Adventuring tree.  The way it plays out, the Empire adventuring tree does feel pretty random (while still having a defined progression).

There's a good number of techs in this game, not counting the repeatable techs.

My guess would be between 80-100.

We do need some more rare ones though.

There was also going to be techs that were only available if you encountered certain resources or completed certain quests; rare techs you might only see once every dozen games or so. I'd still like to see those.

Again, though, I'd like to see them after magic and tactical battles get the overhaul they're due.

You can build a Palace once you research administration which generates 7 Gildar and 7 Prestige. I don't think there's a building that produces research though. IIRC the Mint also generates Gildar too. Would be nice to have similar royal or world achievements that generate Arcane and Tech research points too though (unless they're already in. Can't remember if the current tech and arcane achievements apply a bonus or generate)

I updated my Tech Trees PDF to include some grey shading to indicate rarity (light grey is >= 50% chance, dark grey is < 50%):

http://cid-7d2aef4a0e3e3711.office.live.com/self.aspx/Elemental/TechsTrees.pdf

My guess is that Civ's tech tree is much more streamline - any given tech leads to one or two other techs and there's really only a handful of ways to get from beginning to end (not counting going back). So it's very deep. You're only able to research (generally) a few techs at a time; it's very focused.

Elemental however is very wide. Since techs are basically levels, each tech opens up more and more techs. It's a lot of short trees but there's many to pick from. It gives the impression that there's a lot to research at any one time but that you're not researching deeply since most of the trees only drop perhaps 5 techs deep (Deepest I've seen so far is reaching housing for Kingdom). 

I would LOOOOOVE it if they gave us a selectable option to make things truly random. As in, I would select Diplomacy as my research, but it'd randomly pick which one of the options I'd get when research is done. It'd add a lot more "oh cool" or "Oh shit!" to the game which is sorely lacking.

And please.. please please introduce truly random events. I'd love to get that message at the beginning of turn saying, "sorry dude, a fire burnt down the XXX in your city"... or "sorry chump, theives made off with 20 chrystals" from your vaults... now THAT would rock.

Doesn't seem that should be too hard to implement (this coming from a guy with Zeeeero knowledge in coding/game making! haha)

One of the issues with making it less random is that research in one area seems to increase the odds of finding things in another. Like if I have a red Civics tech on the list and go to research five Warfare things, by time I come back it's turned yellow.

The end result is making it pretty easy to go through seeing nothing but green techs the entire way, which largely defeats the point.

The problem is generation, not bonuses. The bonuses are useless unless you have an ancient library in the city.

While the volcano/resource idea is neat in gameplay terms, it's so many kinds of wrong geologically.
Around volcanos you find basalt, which is only good if you want crappy glass or glassy rocks.
No metal veins, crystals, food, or anything... useful.

But bonus points for magma.
There is no problem that cannot be solved by liberal application of magma.

What about the suggestions talked about in this thread, especially the one where base generation is dependent on city level?

Best regards,
Steven.

In comparison, I've hit Elemental's 'future techs' -- the 10% bonus generic techs -- quite often, and fairly soon in a game (late early stages, or early middle game).

It seems that I'm blowing thru techs relatively faster in Elemental.  Adding new, unique techs would be nice, but perhaps tweaking research rates to slow them down a bit would be also a solution.

I really disliked Civ4's 'future techs' but I realize they're necessary in an open-ended game.  I feel the same regarding Elementals'.  Good game balance to me would be having them very rarely reached in a 'normally' played long game.