Race attributes for each planet type

The problem here is that all races need to end with roughly equal ability to colonize everything. If Torian planets are all so far aquatic that I can't ever use them, what reason do I have to conquer them? It's just going to be a class 0 to me, which means conquering it is effectively destroying the planet. It just becomes genocide runs by a different name.

You don't see a shark and a cactus ever competing for resources - neither can use what the other is using. The same would apply to civilizations in this system. Sure, you might fight over mining resources but fundamental living space would never be up for competition.

I agree the environmental tech in GC2 was pretty shallow, but this may not be the best way to fix it. Maybe expand the environmental techs to 5 levels each, and the farming techs to have to cover each planet type. Maybe other buildings as well. Races could get a head start by starting with different levels of tech for each type but no race is ever permanently locked out of any type if they research all available techs - and they get full use of that type, not one race getting +10 tiles that other don't.

You still have the problem of conquering planets you can't use in Galciv 2 because the other race's technology is more advanced than you when they colonised it. I don't think the argument is valid and having different races use different types of planets in the beginning would make the game more interesting. There will still be common planets that everyone wants for one reason or another and as techs are researched, the playing field is leveled out more and more.

You could have planets with more than one attribute eg: A planet that is desert, volcanic and toxic. One race thrives on desert planets, another on volcanic, and another on toxic so the planet will appeal to all three races at first. As more research is done, other races will also want access to that planet.

I think it could be interesting to have quality based on race, for instance an aquatic race might have a PQ 20 on a normal planet but for land based life may be PQ 10 or vise versa depending on water,  Baron worlds for instance may be PQ 0 for aquatic race at the start of the game until they are able to terraform it to have aquatic area's and even then it would never be as good as an aquatic world.

With this you could have many variations such as custom races you could set your tolerances and so on, and all worlds could eventually be colonized once your tech gets high enough just some may never be as good as others depending on who your race is..

edit:

or as you terraform it becomes more and more your quality planet completely changing a baron world to aquatic after many turns and terraforming level. slowly increasing the PQ overtime until maxed for that planet.

Honestly, that's the best damn idea I've heard about colonization in a long time, very interesting.!

Of course, I can see some problems; 

1. Races that prefer rarer environments will be at a severe early-game disadvantage compared to others which prefer other, common environments unless they had a massive advantage on those planets they could use. 

2. If every planet is colonizable and useful in the late game, we'll have a fuster cluck of planet management in the late game on big maps, like in GCII on immense maps.

3. If every race can eventually colonize every planet, then it removes a huge part of the uniqueness of each race

See bolded. It looks like you may agree with me more than you think you do. Races need to be able to use everything eventually; I never said they should start being able to use all types.

You say that as if it's a problem, rather than the intended endpoint. They provided sliders to adjust things like number of planets last game, it's nearly certain you'll be able to tone down things you don't like this time around as well.

Sharks and cactuses. If there are resources somebody else is using that I can't use, I have no reason to compete for them. If there are planets I can't ever use for anything, there is no point in invading it other than as a genocidal attack on the occupants. You may as well give us planet busters for endgame, since that what each attack would effectively be anyway.

It never has to completely level out in the end; each race's uniqueness could always keep them superior. If every race could, for instance, research up to +30 for a planet attribute by the end of the tech tree, it will still leave the race that started at +20 with +50, while races that started with 0 would only end up with +30.

I'm against the idea of a linear tech tree that has an end BTW. I'm all for infinite research, where you can always research a +1 or more to something, at exponentially increasing costs and time, but that's for another thread such as this one: https://forums.galciv3.com/450312

Maybe the planet penalties are to much. That would be a solution to the problem. This is a nice idea for maybe an option on the game I would play it sometimes othertimes I wouldn't. You would have to make it that if this option was on then all planets would come in an even appearance if you do this as an option to the game. I would have to make the humans Terran, but the other races would come from random types of planets. Why not random classes on starting planets why you are at it. I think this is a nice game option, but not as a main game. If the only ones that start out with terran are humans garanteed. It would not make sense to attack a world you could not use except this guy will not leave you alone. This is at least a nice thing to do with class 0 planets.

i kind of like this idea but possibly make it linked to other worlds for example i have 3 earth like worlds say PQ 10 and i can gain +15 for each of those through research but i lose 5 for being an aquatic race for a total PQ of 60

(assume that an earth like planet is normal and each planet type is 1 step off of normal

so if you like volcanic then earth like is -5 and aquatic is -10

if you like earth like then every other type is -5

if you choose a type other then earth like you get a +10 to that type and an additional +10 from research

earth like planet's are more common and are "closer" to all other types so don't get a bonus)

lets assume the planets are relatively close together and i drain 2 of the planets and dump all that excess water onto the third planet. changing the first two planets to barren and the third planet to aquatic

now i have 2 barren planets which effects me at -10 due to my preference for aquatic worlds  so they are PQ 0 and one which is aquatic giving me +10 but i can enhance the aquatic by another +25  so now i have 1 planet with an effective PQ of 45 and 2 planets which i could research up to 15 granting me a total PQ of 75 or i could turn the two planets into mining colonies which might give my third planet some manufacturing bonus. or i could try and further terraform one of them into a volcanic world and give it to an allied race(who happens to prefer volcanic worlds) in exchange for their new battleship

Lets not forget about all the other sources of Ice in the solar system. Their is about ten times more ice than there is rock. Also gas giants can have water ours do. The above is an ecample for an Aquatic race, but a Terran species would not use as much water. A species from a toxic world would not use water water, but maybe other inert gases from a gass giant. Going off our own solar system with Jupiter and Saturn being class 0 instead of heavy gravity worlds. There may be other examples.

Please make this an option to the game, but not the game that would be fun as long as I could shut this off when I want to play the other game. I think 15 is a little unreasonable maybe we should make it less.

I like this idea. Also, you could get military bonuses when invading/defending a planet which is of your preferred type.

Maybe you can also have a separate "favored terrain" attribute - plains, forests, mountains, etc - affecting how much use you get from the different continents on the planet. Again, this would affect planet defense.

In the game Stars!, a planet has three environmental values - gravity, temperature, radiation - and at the start, you specify the range your race can live in. You can have your species be able to live ANYWHERE - or you can have them be super finicky and get a ton of extra points to spend on other race attributes. You can also terraform planets to fit your race, but changing a planet too much outside of its natural value is pretty hard, so some planets remain more attractive than others. 

Having different civilizations prefer different planets can be a feature - another variable to consider. If you make an ally of a civ that loves planets you hate, you would have much less competition, and together you could make the best use of your territories. On the other hand a civ that shares your environment preferences can interact with you a whole lot easier, fostering good relations, increased trade profits - and more spying opportunities. 

Funny you should mention Stars! I'm pretty sure you could use terraforming as a weapon in that game. You could terraform an enemy's planet from space making it more to your liking and more uncomfortable for them to live in.

This also bothered me about GalCiv2.  A class 20 planet was a class 20 planet was a class 20 planet.  It didn't matter what race you were playing.

The Torians should be aquatic and the Yor should be able to colonize a larger array of planets because they're robotic.  The real question is how to balance this?  I assume pay more race points for being able to colonize a wider variety of planets and less (negative) for being able to colonize only a small section of planets without terraforming.

A planet's class should matter on your race.