Endless Space groups the varying planet types into different groups. By default, only Class 1 Planets will be colonizable, and you unlock the ability to colonize planets in the higher tiers as you move down the tech tree.
By contrast, terraforming unlocks in the reverse order, so, as mentioned, you probably won't have favorable terraforming projects available until late game. Generally though, you have to move up in class if you want a net positive in FIDS - otherwise you're either losing them, or swapping Science and Industry, etc.
You can only have one exploit per planet, so I've listed them separately, as some planet types get increased benefit from multiple exploit types.
Category 1 Planets (11 Base FIDS)
Terran
Base: 3/2/4/2
Tier 3 Exploits: 3/0/1/0
Food:
- +2 Epigenetic Crop Seeding
Dust:
Total: 5/2/5/2 + Exploit
Ocean
Base: 3/2/2/4
Tier 3 Exploits: 2/0/0/2
Food:
- +2 Epigenetic Crop Seeding
Dust:
Total: 5/2/3/4 + Exploit
Jungle
Base: 3/4/2/2
Tier 3 Exploits: 2/2/0/0
Food:
- +2 Epigenetic Crop Seeding
Dust:
Total: 5/4/3/2 + Exploit
Category 2 Planets (10 Base Fids / -5 Approval)
Arid
Base: 2/2/5/1
Tier 3 Exploits: 1/0/3/0
Food:
- +1 Sustainable Farms
- +1 Epigenetic Crop Seeding
Industry:
- +1 Heavy Isotope Refining
Dust:
Science:
Total: 4/3/6/2 + Exploit
Tundra
Base: 2/1/2/5
Tier 3 Exploits: 1/2/0/0
Food:
- +1 Sustainable Farms
- +1 Epigenetic Crop Seeding
Industry:
- +1 Heavy Isotope Refining
- +1 Interplanetary Transport Network
Dust:
Total: 4/3/3/5 + Exploit
Category 3 Planets (7 Base FIDS / -10 Approval)
Arctic
Base: 1/0/1/5
Tier 3 Exploits: 0/0/0/2
Food:
- +1 Sustainable Farms
- +1 Epigenetic Crop Seeding
Industry:
- +1 Heavy Isotope Refining
Science:
Total: 3/1/1/6 + Exploit
Desert
Base: 1/5/0/1
Tier 3 Exploits: 0/0/2/0
Food:
- +1 Sustainable Farms
- +1 Epigenetic Crop Seeding
Industry:
- +1 Heavy Isotope Refining
- +1 Interplanetary Transport Network
Science:
Total: 3/7/0/2 + Exploit
Category 4 Planets (5 Base FIDS / -15 Approval)
Barren
Base: 0/1/4/0
Tier 3 Exploits: 0/0/0/3
Food:
- +2 Wasteless Supply Chain
Industry:
Dust:
Science:
- +2 Non-Baryonic Collider
- +2 Optics Research Lab
Total: 2/1/1/4 + Exploit
Lava
Base: 0/4/1/0
Tier 3 Exploits: 0/3/0/0
Food:
- +2 Wasteless Supply Chain
Industry:
- +2 Interplanetary Transport Network
Science:
Total: 2/6/1/2 + Exploit
Category 5 Planets (12 Base FIDS / -20 Approval / Cannot Terraform)
Gas Methane
Base: 0/10/1/1
Tier 3 Exploits: 0/1/0/0
Food:
- +1 Wasteless Supply Chain
Science:
Total: 1/10/1/2 + Exploit
Gas Helium
Base: 0/1/1/10
Tier 3 Exploits: 0/0/0/1
Food:
- +1 Wasteless Supply Chain
Total: 1/1/1/10
Gas Hydrogen
Base: 0/1/10/1
Tier 3 Exploits: 0/0/1/0
Food:
- +1 Wasteless Supply Chain
Science:
Total: 1/1/10/2
Asteroid Belt
Base: 0/4/4/4
Tier 3 Exploits: 0/0/0/0
Food:
- +1 Wasteless Supply Chain
Industry:
- +1 Interplanetary Transport Network
Total: 1/5/4/4 + Exploit
Terraform priorities will come in a bit.
The first ships the AI makes will always be ballistic, because it makes some defensive ships asap and that's the only technology available to it at the time.
From peaceful races you have more chance to see a lot of ballistic because they tend to research other areas that fit their play style better (production, growth, diplomacy, happiness, etc). But when you are facing warlike factions, you will see more variety of weapons because their "war technology budget" is higher. This seems to be especially true for Hissho and Cravers, then empire to some extent.
Another factor to this is the difficulty level. You will see more variety the harder mode you use. I play on Serious and i tend to see a lot of variation in weaponry. In my current game my Hissho enemy has mixed ballistic, missile, and plasma weapons all in the same fleets he use against me.
So yes, you have to get a feel for this and scout properly. You can suicide a scout ship from time to time to check, but if you play on higher difficulty it is generally better to build ships that are ready for all situations. The most common strategies you find are :
1) A swarm of destroyers with weapons only and no defense. The idea is to play a kamikaze tactic and keep producing them non stop.
2) Using battleships with very high resists so they become near invulnerable to damage. The ratio is about 2/3 of the weight in defense.
My preferred tactic which i developed is not very popular, perhaps simply because it is not known yet, is to make missile boats with no defense modules other than the extra health from support. I do 1:1 weapon to health modules, focus on +health techs, and use the repair card every time. The idea is that with more health, you get more regeneration from repair, thus can survive the first and second phase of battle, while your missiles will almost always kill the enemy on phase 1 with the massive burst damage.
I hope this has answered your question. Good luck with the game.
Best Answer
That icon indicates ship or planet sensor range. It denotes how far away you can see enemy ships and colonies. The higher, the better. There is no downside to having larger sensor ranges (other than improvement maintenance costs).
Ships can get sensor package upgrades, which will allow them to see further, and make ideal upgrades for scout ships. These upgrades increase sensor range by:
Star Systems also have sensor upgrade packages, which the primary use of are for early detection and warning systems. The further away you can detect incoming enemy ships, the more time you have to move ships to defend the planet. These upgrades each provide 10% to sensor range:
Sophons also get a racial unique upgrade that provides +20% to sensor range: the Predictive Sensor Array.
Your heroes can also help increase the sensor range of planets with Abilities:
I couldn't find any data about star system's initial range, unfortunately. Each planet should have the same range, sans improvements/hero abilities, once they become full colonies. Note that planet influence increases with population; that's the colored circle around your planet; sensor range is the colorless circle around ships and planets.