What is PQ?

Planet Quality. It refers to the number of currently usable tiles (for building stuff) on a planet. So higher is better, of course.

So when people say nothing below 8 or 9 they don't touch? why? wouldn't it be good to just have research or market stuff on those 4 tiles or what not?

Actually: -

From Wikipedia, the free encyclopedia

In mathematics, a semiprime (also called biprime or 2-almost prime, or pq number) is a natural number that is the product of two (not necessarily distinct) prime numbers. The first few semiprimes are 4, 6, 9, 10, 14, 15, 21, 22, 25, 26, ... (sequence A001358 in OEIS).

Currently, the largest known semiprime is (232,582,657 − 1)2, which has over 19 million digits. This is the square of the largest known prime number; the square of any prime number is semiprime, so the largest known semiprime will always be the square of the largest known prime, unless the factors of the semiprime are not known.

Semiprimes are highly useful in the area of cryptography and number theory, most notably in public key cryptography, where they are used by RSA and pseudo-random number generators such as Blum Blum Shub. These methods rely on the fact that finding two large primes and multiplying them together is computationally simple, whereas finding the original factors appears to be difficult. In the RSA Factoring Challenge, RSA Security offers to award prizes up to $200,000 for the factoring of specific large semiprimes.

In practical cryptography, it is not sufficient to choose just any semiprime; a good number must evade a number of well-known special-purpose algorithms that can factor numbers of certain form. The factors p and q of n should be very large, around the same order of magnitude as the square root; this makes trial division and Pollard's rho algorithm impractical. At the same time they cannot be too close together, or else another simple test can factor the number. The number may also be chosen so that none of p − 1, p + 1, q − 1, or q + 1 are smooth numbers, protecting against Pollard's p-1 algorithm or Williams' p plus 1 algorithm. These checks cannot take future algorithms or secret algorithms into account however, introducing the possibility that numbers in use today may be broken by special-purpose algorithms.

The value of Euler's totient function for a semiprime n = pq is particularly simple when p and q are distinct:

φ(n) = n + 1 − (p + q)

Hope this helps

Sub PQ10(ish, cant remember the exact number) cost too much to maintain in the early stages of a game.

??????????????? lol that confused me lol, why would it cost too much? in what way, still learing the basics of the game, not so shure how economics work, right now, rush buying some factories and having a -16 to -35 credits per turn for a bit then build some markets on my 4 tile plantes, that no good strategy?

I think they are usually talking about early in the game. It's one of those things where you are racing the computer to colonize as many planets as you can right off the bat. You can only produce so many colony ships at a certain rate, so it often pays to be picky at the start. Taking a PQ 7 planet early will usually mean you missed out on a PQ 10 or something in that range.

Once you have established a number of planets on decent quality planets (I don't pass up PQ 9's...I have to think about PQ 8's and decide if the location is worth it), then you can consider taking the 7's. I usually won't bother with 6 or lower, though, because colonies drain resources as they start out, and early economy is very important. Even with 7's I will often leave them be if they are sitting in the middle of my empire. You can flip them easily with influence after someone else colonizes them.

That's just how I normally do it.

hmm, i thought if i just built or bought some market buildings it would help, and keep my empire close just in case of an attack, they would be hit first instead of over extending my reach.

The game is really a balancing act, at least at the harder difficulties. You have to expand fast, but you also need to develop tech and military quickly or you will get swamped by the computer. So this means you have to be very careful with where you put your resources.

When colonies are created, they do drain resources pretty fast in the early game. The low level techs don't provide enough benefit to make the really low PQ planets worth it early on. Moral is also a problem early on, which only makes matters worse for the little planets.

hehe, you have to keep in mind that many of the posters here who give advice play on the hardest difficulties. When you get into the upper difficulties, you have to tighten up your playing strategy or you fall so far behind you have very little chance of ever digging yourself out. On easier difficulties, the computer gives you a lot more leeway.

You need high level tech to make low PQ planets even marginally profitable. You just don't have that early in the game, and colonizing one will just make you miss a chance to expand into a PQ 10 or better somewhere a bit further out.

Sometime try leaving the PQ 7 or less alone if they are in the middle of your empire. Once you get established and the game has gone for a while, then move to flip them with influence. It's very easy to do, and now you have a planet that's partly built up.

You need high level tech to make low PQ planets even marginally profitable

Plus they cause a large drain on your starting finances if you colonize them.

All of the above are basically true. PQ4's can only grow to 2.5B on their own, PQ5's will grow to 4.4B (read the wiki article about pop). There is really not enough pop to generate decent taxes nor enough space to place enough economic building to make them economically worthwhile. The best thing to do with them is make them research planets but that's for later in the game as well. Yes, you can put 3 factories and a spaceport on a PQ5, particularily if it has some manufacturing bonus, but again I'll do this later. Also because of the pop growth limit they don't generate much influence. I like to leave PQ4's, PQ5's and PQ6's open for the AI to come in and waste a colony ship and spend money developing them, they inevitablely flip to me anyway by the 2nd or 3rd year. PQ6's are a bit better than 5's bit still will only get to 6.9B on their own. I generally don't bother with a farm on a PQ6 (unless it improves) so that will limit it to 5B.

There is an off chance that I'll colonize a low PQ planet to ensure continuity of my influence area, but's it's rare and really dependent on galactic geography.

The other thing to consider is the potential for improvement. PQ4's and 5's seldom get any extra tiles as you research the terraforming path. PQ6's may pick up a tile, and perhaps rarely even two, PQ7's usually pick up a tile.

PQ7 is where I personally draw the line. They'll grow to 10.2B on their own which is not too bad. They're worth putting a farm on even if they don't improve. I'll pretty much ignore anything less (early). I generally take a look at the system the PQ7 is in and if it's the smallest or only low PQ planet in the system I'll probably ignore it. If there are lower PQ planets in the system I'll probably take it because I don't want an AI to outnumber me in one of my own systems.

PQ8's will grow to 14.6B on their own and usually increase to PQ10 once you have all the terraforming techs. I'll take a PQ8 every time, no questions asked.

One final point that was not specifically asked but I think is important. Certainly, when you have an equal choice go for the higher PQ planet. But if it's going to take you an extra 4 turns to get that juicy PQ16, I'll go for the PQ8 that I can get to in the next turn, unless it's obvious I can get the PQ16 if I go for it but will probably lose it if I wait. The reason for this is that growth in this game is exponential and a mediocre benefit early is better than a great benefit later (I've said this elsewhere as well). If by grabbing the close PQ8 you get four extra rounds of development over waiting for the PQ16, it's better to take the PQ8.

Still, it is pretty annoying to have a civ infiltrate your empire by colonizing all those puny planets you ignored, as it blows your sector influence, for one thing.

Still, it is pretty annoying to have a civ infiltrate your empire by colonizing all those puny planets you ignored, as it blows your sector influence, for one thing.

I understand the feeling, but it's also a benefit to conquer a bunch of planets without firing a shot and without having to expend your own population as troops to eliminate the planets original pop so that you can start over.

I also take care not to give them too many planets in the same system or too close together.

Finally, as your racing for that last uncolonized PQ16 wouldn't you rather the AI took the lousy PQ4 in your home system instead?