Having a strong army in Star Kingdoms is of course an advantage, but if you don't know the stats of people which you are going to attack, there is usually no use attacking, since you will either fail or send ways too much.

Having many probes does not only make it easier for you to be successful when probing people. Other people will also have a harder time probing you (unless they have even more probes).

To get a strong probe defense, there are usually four good guidelines to follow:
•Build up your probe defense so that you never get a bad probe ratio. During the first days, you can just attack inactives, and usually won't have to probe people at all. If you start losing probes, you end up in an evil loop, where you fail because you have a bad probe ratio, which makes your probe ratio become even worse, so that you fail even more.
•Have many probe factories. Most persons have factories on 15-20% of their land at the beginning and 5-10% later on.
•Never probe a person if you know that you will fail. Failed probings make you lose a lot of probes, and since they are unsuccessful, they don't give anything at all.
•Shield the probes. It only takes a couple of hundred extra powerplants to be able to shield the probes. When doing so, you will not lose many probes at all, even if the probing fails, and you are also a lot more likely to be successful. If you have power which you can spare, always spend it on probe shields.

The different probings
Spy on Kingdom(SoK) - gets Kingdom stats of a kingdom, showing his total army, resources, and many other interesting things. You usually get those stats if you want to see if a target has power, or if he is a good bank. If the kingdom is inactive, you should only get those stats instead of a SoM.
Spy on Military(SoM) - Shows detailed information about the kingdom's army, how much military he has out, and when it will be returning. This is usually the only stats you actually need to attack someone.
Spy on Buildings(SoB) - Shows information about the kingdom's different buildings, and what he is constructing for the moment.
Spy on Research(SoR) - Shows information about the kingdom's research.
Spy on Shields(SoS) - Shows information about the kingdom's shields. Military shields (max 10%) gives a decrease to the offense of kingdoms trying to attack him. Missile shields (max 50%) shields the kingdom against missiles fired at him, and Probe shields (max 30%) which makes people who probe the kingdom fail more often.
Spy on Sector News (SoN) - Shows the sectornews, with all the attacks which the kingdoms have made recently. If you make a SoN probing, you should do it on a small kingdom in the sector, since they usually have less probes and therefore are easier to break.
Rob Banks - The probes steal a maximum of 1/10 of the kingdom's money, or 10 money/returning probe, whichever is the least, and returns that money to you. You can use the spreadsheet in the menu to the left to find possible banks in an easy way.
Arson - Destroys a maximum of 5% of the kingdom's residences, or as most 1 residence/1000 probes.
Sabotage Powerplants - Destroys a maximum of 5% of the kingdom's powerplants, or as most 1 powerplant/1000 probes.
Kidnappings - Makes a kingdom lose as most 5% of his population, and returns 1/4 of that amount to your kingdom.
Suicide Attack - All the probes which you send will die, but they will destroy 2 power each, if successful, which means that probe suicides might be a good way to get a target powerless very fast in wars. At all other occasions, it shouldn't be used unless you are about to hit someone which has almost no power at all saved up (some people use almost all their power for shields, and leave an excess of maybe 500-1k power, since they know that they will get new one the next hour).

Probe losses when sending shielded probes on a successful probing mission are either 0.275% or 0.55% of what you send (decided randomly). A successful unshielded probing gives 1.1% to 2.2% losses. If you fail, you lose far more probes than this, so it is better to send a bit too many probes and make sure to be successful. The Probe Armour research also decreases all probe losses with 50%.

Robbing
The difference between an average-sized player and a big player is usually decided by how well they can find good banks. Many good players rob more money every hour on average than their hourly income, which makes it possible for them to grow far faster than most other kingdoms do. To find a bank, you just compare kingdom stats, or entire sectors, before an hour change, and after the hour has changed + the sector has been updated. Kingdoms gaining a very little NW and no land are usually good banks.

There are only two things which you have to think about when robbing people. First of all, it is good to spread the probings a bit. If you rob someone ten times in five minutes and fail the last time, he will realize that all those probings are made by you, and probably be quite angry when he logs on.
Secondly, kingdoms might have Frequency Decryption Center researched, which makes it possible for them to find out who probed them, even if that person didn't fail. Desert Wasteland kingdoms always have this bonus maxed (on 25%), so watch out when probing those.

If you rob money from a kingdom, you will gain less money the next time you do so. The robbing calculator below will help you to determine how many probes you should send the next time, to gain as much money as possible and still not have to send too much. Just enter how much money you gained for the last robbing, if you will send the probes shielded or unshielded (by checking the box), if you have Probe Armour researched, and press the big button, and the perfect amount of probes to send will be calculated for you.