Quite frankly as the game progresses we all become a bit more informed about what a good planet is and isn't. In addition, our own personal standards as far as what's worth invading vary. I want to somewhat standardize that.

• If I have [planet's stats] should I invade it?
  that are some crappy planets that no one should take
• If I have [planet's stats] what should it be producing?
  I've seen too many maxd toxics just sitting there bricked
• How should I defend this planet from those that also would want it?
  What kind of players would be attracted to this planet?

Low ranks?

• Then just put a little defense and some cloak.
High ranks?

• Cloak it well enough so they won't find it.

For example, a Very large extremely rich artifact planet is still worth the invade for me (some other players might disagree with me on this) because I know I can max production to 200 arti/hr.

However, on the other end of the spectrum, a very massive 15x artifact planet is clearly worth to anyone, but what is the minimum it should produce? What amount should be invested towards defense and cloak?

I think that also varies as players move around in rank. At the moment I dont have the ap or attack to find and invade lots of 15x planets so I invest much more into any that I do get. Personaly I try and permacloak them, but others will often just put some defence and a bit of cloak on and max production.

As for my personal standards, I only do ultra rich vl or above (or equivelent) even on colonizations.

One of the things I look for is a minimum of 200 production. Though I think that may be a bit low considering what I am seeing from some players. Typically, Very Large and up. You can't adequately cloak a planet smaller than that but you may encounter nice production planets smaller.

I've lost nice planets with lots of defense. So I have given up on that and don't really bother anymore. Any planet I wish to keep has at least 20k-30k cloak. can still get good production out of those planets.

so a lower ranking player takes a planet from you. chances are it is one you really don't care too much about if you have cloaked it properly. Either let them have it or since they probably haven't fluxed it, just take it back.

Of course this means I don't have all of my planet slots filled as I haven't found enough to meet my standards.

learn from my mistakes ...

i have a S ER icy ... that i have colonized 3x ... and abandoned twice. initially it was making 100 arti per hour ... then got flushed when i ran out of planet slots due to ultra slow ranking. then a big dry spell meant that i had 25 open planet slots. figured i might as well be using the production space so welcome back ! again got tight on planet slots and a juicy planet was alerted. so bye bye #2. then, as i was going thru and adjusting my weaker planets for pure production status by removing superfluous defenses and cloak ... i figured that even a small ER planet would be worth over 150 aph as an excavator, with only a meagre chance of someone taking it (and even then ... easily replaceable). so colonize #3. and i still have it hundreds of ranks later ... so that extra 150 aph times many months ?? easily worthwhile.

so, as your rank increases, your planetary pickiness should increase. also, planets that were once worth defending, begin to be worth more as pure production as you have to spend your precious defensive artis on better planets. the more open planet spots you have, the less pickier you can afford to be, as you have to weight the opportunity cost of leaving those slots open versus the extra production. the other variable is production cap. if you are already capping production in a short enough timeframe to eat into sleep, your planet standards for the next invasion / colonization need to go up until you have either built more storages or ranked up to give yourself more cap space.

also, the types of planets you keep around will likely change. while research is still an issue in the early stages, gas planets and research icies are nice to have around. but once you have the researched mods that you are aiming for, the gas planets can be transformed into storage plasmas ... but the research icies will likely go the way of the dodo unless you are willing to spend extra effort to uplift them ... but this comes at the expense of arti icies ... so sometimes it makes more sense to abandon them. so there is a situation where gas > icy.

for mining, volcanics give you the best boost compared to toxics without any uplifting, but once you have access to toxic purifiers, then those volcanics are a drag. i still have a couple of demons from invasions, but none of my original volcanics are still on scan. metallics have gone in and out of favour for me ... the fact that you can find them naturally VM meant that one planet could switch between mining / research production depending on which one needed to be supplemented / varied to fit within your production cap. but then arti planets became key and most of the smaller metallics went goombye. now i want to get a few more metallics in stock to try to attract gauss chains, but with the idea that the VM ones can eventually also become storage planets now that litheor core tunnels and polaron emitters make that an alternate option.

as for arti planets ... this is also rank dependent as some nice artis only show up in high level legion missions or npc drops. so someone at rank 300 may have very different expectations for an arti planet than someone at rank 1500. and as new artis get released, the calculus changes, depending on what else is already on the planet and whether you have sufficient extractors / race changes to make the structural alterations for increased productivity. as long as your arti / planet ratio goes up over time / rank ... you are doing okay.

so the final answer after all that ? IT DEPENDS !

I am on the extreme edge here with planet production.
Rank 1893 with 193 planets but I make 144k arti/hr as excavator.

The following planets are with no moons/rings/ruins/SS or hoveroids or excavator bonus. The builds for these are completely repeatable without spending any GP. All structures bought with badges or dropped from NPCs or legion missions.
Very Massive 15x artifact ~ 800 arti/hr
Massive 15x artifact ~ 675
Massive 5x artifact ~ 425
Very Large 3x artifact ~ 340
Large 1x ~ 250

Above the VM 15x planets there's way too much going on with planet effects and which limited artifacts or GP bought artifacts you have to throw at the planets.

Currently rank 151, 22415 AP/h and 35 planets, giving a AP/planets value 640.2. This is actually low-balled atm, since I have several finished projects coming in soon.
So you see, with some planning and determination, you can also get a very high AP PQI without being a high ranker or being in EotS

For me, as a slow ranker and trader, I wont colonize it unless its atleast either:

A 2x MR
L 1x MR
VL MR
M ER/UR (depends)
VM ER

This means each of those planets currrently makes me 250 AP/h before excavator. With tweaks to always push them higher, in late game they can approach 300 AP/H

If Im very tight on slots, I will either:

- leave the last slot or two open for a project planet, or
- wait til I scan something in the VL 5x+ MR range (planet must be able to make 500 AP/h)

My rules for top-tier planets are (these include excavator bonus, and usually a hoveroid):
A basic VM 15x needs to be able to make 1000 AP/h without any limited artifacts.
A project VM 15x needs to make 1500 AP/h (this one is actually hard, but ensures the 2k final goal is met easily)
A finished project must make at least 2000 AP/h

Rank 2888 here, 272124 aph with 493 planets occupied; here is my feedback:

Planets always worth invading:

Any VM or bigger arti planet (best kind of planets to terraform)
Planets with extractable cloaking artis (CSR / Ergo / Meta / LCT / etc)

Good arti planets with inactive owners (350+ aph)

Planets with GP stuff (warehouses / scruuge vaults / etc).

Once invaded, if I don't want to keep the planet I use research optimizers to make it 15x and leave it undefended; most of the time is taken back if the owner was active (else at least is producing extra credits).

I do not colonize planets anymore, but just because I'm waiting until I get my 3rd year reward in December (then I will colonize 100 planets in one go if all goes as planned).

As a general rule for planets:
Research:17x colossal plasmas only, leave undefended
Mining: 16x / 15x VL toxics only, leave undefended
Artifact ("meh"): ~220 aph, up to ~400 aph, leave undefended
Artifact ("great"): ~700+ aph production, at least 18k cloak

Storage: use the colossal plasmas from above once you don't need research; easy to cloak to 18k+ using satellites and a polaron emitter - 5 arti warehouses and a poly vault only on each one (very cheap to make, and if lost - which is next to impossible with so much cloak - it's just 4k ctp).

The arti planets in between "meh" and "great" (e.g. an average 9x arti exotic), I usually focus on production but I probe them from time to time.

Don't invade any mining or research planets unless they have something from the first list, and avoid making too many.