How to Invade An Alien Planet

''So you're traveling the space lanes, looking for some ripe planet to invade and loot. Here are some tips to ensure you don't end up like all the others out there who've tried and failed. All we request for giving you this information is, should you successfully invade a planet, that you give us some of the fruits of your labor and possibly positions of power on the planet you invaded. Preferably far away from the planet in question.''

Phase One: Motivation and Planning

 * 1) If you're looking for some ridiculously common substance like helium, water, oxygen, etc., there are millions of lifeless rocks where you can get the stuff essentially for free, without the need to fight off pesky hostile natives. Aluminum? Uranium? Go mine an asteroid and leave the Puny Earthlings alone.
 * 2) Free advice: water is bulky. Even a fleet of a thousand mile-wide spaceships can't hold enough to make a significant impact on a planetary biosphere. If you need it for reaction mass and not to drink, see #1. In fact, if you don't need it for reaction mass and do need it to drink, also see #1 (sure, it's dirty, but you can clean it up with simple distillation—and probably get some nice salts, hydrocarbons, etc., in the bargain).
 * 3) If you're sufficiently advanced to cross interstellar space in the first place, consider investing some research into basic technologies like food replication. Harvesting native intelligent beings as cattle is dreadfully inefficient, and they tend to object. And if you are looking for a bite to eat, you might want to try abducting large, meaty animals instead of wasting your time with the boniest, least nutritious species on the planet—to say nothing of the only species on the planet capable of understanding what you're doing and taking exception to it. With guns.
 * 4) Similarly, unless your robots are really dumb and only sentients can do a job you can't or won't, don't bother going to other planets to enslave the population. Better yet, buy/steal their automation technology instead! (By the way, how did your species get into space without it?)
 * 5) Check the air and water first to make sure they aren't toxic to your kind. If you're invading a Class M planet but your species has a lethal reaction to H2O, natural selection hasn't been doing its job.
 * 6) Take samples of the plant, animal, and microbe life and do controlled studies to make sure your mighty invading army won't be killed by a bacterium. Further, test all of these samples to ensure that they don't have non-lethal but disabling or embarrassing effects on your biology like ginger making your troops horny or sour milk making you drunk. Lastly, cross-check your and the invadees' relative scale. There's nothing more embarrassing to the average galactically-feared alien conqueror than commanding your vast battlefleet across the interstellar void and into a screaming dive upon your target planet with all weapons blazing, only for it to be swallowed in its entirety by a small dog.
 * 7) Bring a fully-equipped scientific staff to deal with any unexpected issues that may crop up (and they will). Treat them with respect so they don't revolt on you.
 * 8) If the air, water, or biota are hostile, and you can't find a solution that doesn't involve covering your people with inch-thick environment suits, leave. Corollary: If the ecosystems are hostile, and you're after something underground, consider burning the offending biospheres off with an orbital bombardment. Your guys will still be in life support suits, but you'll save money on security.
 * 9) Do some basic research on the history of your target planet—you shouldn't even need to make contact for this as any planet technologically advanced enough to be a threat to you is going to be broadcasting information like crazy. If they've got a history of thwarting invasions and bringing unstoppable galactic juggernauts of destruction to heel? Run right the fuck away, or if your diplomats are skilled enough, and you can offer a big enough bribe, point them at your enemies. Naturally, if the inhabitants of your target planet appear to possess implausible levels of martial prowess, be sure that the information you're observing is non-fiction.
 * 10) Never make assumptions of how rapidly the native species advances. If you come to a planet assuming that they'd still be wielding sticks and they're actually developing the atomic bomb, you're in real trouble. Especially if they are now arguably more advanced than you.
 * 11) If your research is performed from a distance such as your home planet using high-powered telescopes, note that you observe light patterns as they were when they were projected from the alien planet. If you are doing your recon from two hundred light years away, even if your travel time was zero, the data would be two hundred years out of date.
 * 12) If the only threat to your rule is isolated or tied down somehow to a single geographic area such as a city or country, take care of them last - get entrenched first. Conquer everything out of their range of protection first, then lay siege to the remaining area. Use your now-superior amount of the planet's resources to overpower them with sheer numbers and superior weapons. Both, not either.

Addendum: Some particularly hardy specimens will continue with guerilla warfare even after this point. Carpet-bomb the area when you've got him pinned down. Try rodding them first, so you can go in immediately afterwards. If you have sufficient quantity and shielding, try using free-neutron emitters. If either of those don't work or are unavailable, then go to nukes. Preferably from orbit.
 * 1) If the planet's defenders are low in number and ill-protected civilians, don't try to take them out in open combat. Local assassins and mob hit contracts work much better due to sheer experience in killing their own, and can't be stopped or detected by anything specialized to fight or detect you, so, before doing anything else, just bribe an amoral greedy native to take out his own defenders first, and make sure they finished the job. Then invade properly, again beginning with areas the defenders couldn't access if they were still alive (assume that they survived just in case, it won't hurt).
 * 2) If for some reason you can't identify the defenders, just carpet-bomb the area once you reach the "invade properly" stage. Once again, try unleashing the neutrons, then rodding, then nuking. No need to make the planet uninhabitable for yourselves.
 * 3) If your plan is to Terraform the world into a climate or environment more suitable for your own kind, once again, step one is to see if some uninhabited rock will do. If you're sure it won't, then exterminate the aboriginals before commencing operations - you'll be destroying their civilization regardless, and aboriginals are often shockingly adaptable and determined to survive terraformation.
 * 4) If your plan is to, by one means or another, Terraform the planet before you arrive, take the time to scan the hopefully-hospitable planet before approaching. The locals may have interfered with the terraforming process, and at least a few have probably survived, and if - or more likely, when - they figure out you were responsible for the end of the world as they knew it, they will be pissed.
 * 5) If you have an insatiable desire to eat souls, have you considered manufacturing them? Souls are software objects: investing in the mass simulation of innocents is both cheaper and safer than eating out.
 * 6) If your civilization has a piece of Lost Technology that was lost in this sector of space, always always always assume that the natives have found it, reverse-engineered it, or know how to use it, and plan accordingly. If you believe that your invasion will be utterly destroyed if the natives use this technology, just don't bother.
 * 7) If you are biologically compatible to any degree with the aboriginals, even if it's just being able to consume one another's flesh for nutrients, then make sure not to ignore the issue of germ warfare. If you can eat one another, it means their bacteria can kill you and yours them, and neither of you will have any immunity. Send robotic or expendable scouts in first to collect samples (see the abduction recommendations in the Meeting the Locals section for details), and run a thorough vaccination program on anyone who will come into contact with the natives.

Corollary- try infecting the local population with a disease that your own people are either mostly immune to or only mildly inconvenienced by- although this tactic is one best done after inoculating your own troops against the indigenous pathogens to avoid a massive backfire. If you're lucky, their population will be devastated and their civilization in utter chaos, making conquering quite easy and leaving large swaths totally unoccupied.
 * 1) Check the enemy for signs of a Alien Monitoring Agency BEFORE you invade. If they have a Dangerously Genre Savvy one, don't bother. If however the agency is non-existent or is A Half Dozen Guys in A Basement, you may be okay. If one of its agents is a certain Fox Mulder, your chances are about 50/50: although he knows exactly--exactly—what you're doing, there's a good chance nobody will believe him anyway.
 * 2) You may think it brilliant to simply go back to an earlier time in history; before your target victims discovered warp-speed, phaser guns, and teleporters, and the height of their technology are snazzy digital wrist-watches. Just remember, chances are you won't be the only one trying to alter history. And folks won't be pleased that you're trying to destroy their ancestors. In addition, be aware of the tendency of primitive humans to have access to magic. Nothing breaks morale more than having half your fleet taken down by a wizard on a hill.
 * 3) Can you trade with the locals instead of conquering? Many planets even practice slavery, and they certainly will like your new technology. Just remember to trade them microwave ovens, not death rays.
 * Might want to be careful with the microwave oven tech, unless you fancy the risk of being toasted with MASER weaponry.

Phase Two: Meeting the Locals

 * 1) Hire a really good cultural interpreter to help you get around those unfortunate misunderstandings that occur when you are dealing with alien language and customs. It really damages any occupation attempt when the first thing thing the locals hear you say is how your hovercraft is full of eels rather than how your spacecraft is full of orbital-bombardment cannons.
 * 2) If you wish to "learn" about the anatomy/biology of the locals before destroying them (and still wish to remain hidden), make sure you abduct specimens who either won't be missed or won't be reported missing, i.e. a homeless local or someone who lives in the middle of nowhere.
 * 3) Unless you implant some sort of mind control device into the specimen without killing them, never, ever release them back into the general public if you don't want your cover blown. Although, depending on the species, the others may or may not believe the abductee. It still doesn't hurt to not take a chance.
 * Also, be absolutely certain that the abductee isn't an associate of a future La Résistance leader and/or member.
 * The way to tell is that female leaders of La Résistance are always irresistible to young male members of the human race. Male members are always skilled in all forms of combat, so you considering how you were able to carry out the abduction in the first place might be wise.
 * Alternatively, just try and steal some of the native's own studies on their biology, they've spent much longer than you at learning their own anatomy.
 * 1) If you really do come in peace, expect the locals to speak a very different language from yours. There will have to be a great deal of time invested in decoding and learning the mode of communication well enough to establish diplomatic relations.
 * 2) If you don't come in peace, don't even bother and just start invading. Any time you spend learning about and infiltrating them via subterfuge and public relations is time you are giving them to learn about you and your weaknesses and limitations via spying, ill-conceived dropped factoids, and basic behavioral habits.
 * 3) Don't pretend to be "just passing through" when you have clearly studied the native culture well enough to look exactly like them, speak the language fluently, and understand their societal and cultural issues.
 * 4) Helpful hint: appearing out of nowhere over dozens of cities at once in giant ominous spacecraft is not good for public relations. Figure out how the natives communicate and talk to their leaders a bit first. Give them time to prepare for the culture shock. The exception is if you immediately start obliterating said cities. See Phase Three.
 * 5) Don't try to look too much like the natives. Uncanny resemblances breed suspicion. Unless there's some kind of weird universal convergent evolution going on, in which case explain this ahead of time.
 * 6) If you are really V|reptilian monsters underneath those disguises, have a contingency plan for when the natives figure this out. Better yet, come as yourselves. The natives will get over it faster than if they find out you're hiding something.

Corollary: The great thing about being up front about your non-nativeness is that no one will ever imagine you can use spies, moles, saboteurs or sleeper agents. Won't the natives be surprised when anyone from the janitor to their supreme leader can be one of you?
 * 1) Don't try to lure the natives with the promise of sex. Sooner or later they'll actually want some and; (a) figure out you can't provide; or (b) do it and end up giving birth to some weird Half-Human Hybrid with magical powers that will be turned against you.
 * 2) Don't try to supplant the natives' religion. It never goes well. Instead of friendly natives, you've now got a bunch of mindless grovelling sycophants and a bunch of violently outraged fanatics who will stop at nothing to kill you.
 * 3) If you're sending scouts down to the planet, make sure none of them are the type to sympathize with the natives and either defect or sabotage your plans.

Corollary: don't mistreat or kill your own workers. They will defect and they will tell the natives exactly how to crush you.
 * 1) Analyze all native government and military databases, especially small or little-known organizations. Also look into native legends and myths. If they indicate that your intended conquest has an alien protector, a secret project that has already made contact with alien species, a stockpile of alien artifacts, or some other recurring righter of wrongs, run. Just run.
 * 2) Any infiltrators should be closely monitored for defection. Should there be strong or conclusive evidence of such, they should have their security clearance revoked immediately and be detained in a holding facility, preferably far away from the target planet, not guarded by anyone they could ever possibly have met, and certainly not anyone sympathetic. And by immediately, we mean "have that changed in the system now." Just because you took away their key- and identification cards does not mean that they don't have another stashed away somewhere.
 * 3) If normally objective scientists suddenly claim an ostensibly supernatural phenomenon, such as the natives' version of God, is both real and scientifically verifiable, do not dismiss them out of hand, no matter how much easier ignoring it would be. Halt all operations that might be affected, have their results verified by independent scientists, and tested by another group of scientists, with full procedures observed as much as possible. If they are correct, modify or cancel operations accordingly.

Phase Three: Conquering the Locals

 * 1) Study the native technology to make sure that your super-advanced weaponry isn't startlingly inferior to its mundane equivalent.

Corollary: Never underestimate the enemy's ability to improvise.

Second Corollary: Analyze their technology from every possible angle. Is there anything seemingly harmless that could be used as a powerful weapon? Be sure not to overlook easily-weaponized non-weapons technology when making a threat assessment! (See those big cats over there? Ask them about this one; will they have stories to tell). Keep in mind that depending on the species, an effective Lotus Eater Machine and an advanced military training simulator may turn out to be the same thing.

Third Corollary: Make sure they can't use your weapons or easily reverse engineer them. Your technological advantage in combat exists only as long as you and your allies are the only ones using said technology.

Fourth Corollary: Don't be too proud to steal ideas. If it works well against you, it might work well against others.
 * 1) Rig any of your technology that the natives could possibly capture with a foolproof remote-controlled Self-Destruct Mechanism.

Corollary: Make sure the enemy is not skilled in Hollywood Hacking first. Nothing quite compares to your invasion force dramatically exploding moments from final victory.

Second Corollary: Make sure that you have an override code to execute this destruct in the event your people try to use the equipment they were issued against you.
 * 1) Make sure your infantry weapons don't have infinite ammunition. If the natives capture them, it will come back to haunt you. The best course of action is (if you can give them bottomless magazines in the first place) to use gene-locking to limit them to your troops.
 * 2) If your invasion armada has a mothership, make sure it's indistinguishable from the rest of the fleet. Doubly so if its destruction would disable your armed forces.

Corollary: it might be worth it to invest into telecommunications and keep the mothership in orbit where it can't be taken out by 12 marines with rifles.

Corollary: Expect the best native tactician to spend hours studying recordings of your maneuvers searching for weak points. You mothership should not be recognizable even under this level of scrutiny.

Corollary: If you absolutely have to have an ostentatious mothership, have at least one class of ship that is bigger and more obvious, or make it part of a regular class of ships. To many civilizations, Bigger Is Better is usually an indicator of major firepower or command, and will tend to focus efforts on them.

Corollary: A single small ship hanging back from the main engagement is also an obvious target and therefore a bad place to command your operations from, especially since actions against it will tend towards using a Ragtag Bunch of Misfits who may well be more effective than the regular enemy force.
 * 1) If your objective is to conquer the planet and Kill All Humans, just do it. Don't beat around the bush—if you've traveled across light-years to get here, you've gotta have some pretty decent weaponry. The longer you wait under the pretense of being friendly, the longer the natives have to organize a resistance and find your weaknesses... or call for help.

Corollary: If you are going to Kill All Humans, damn well finish the job. Those scattered bands of pitiful survivors may look pathetic and harmless now, but give them a few generations to build up their numbers and you have a bunch of determined, bitter opponents who are very good at not dying.

Second Corollary: If your interest is not specifically in wiping out only the dominant race, consider orbital kinetic bombardment that will reduce your target planet to, at best, a blasted wasteland and at worst a pile of molten slag.
 * 1) Put a firewall on your Master Computer so they can't disable your Deflector Shields with the Melissa virus.
 * 2) If an older model scout ship that you lost contact with decades ago suddenly shows up in the middle of your invasion and wants to dock with your mothership, don't let it. Quarantine it and make sure that it's not the natives pulling some trick on you. In fact, just shoot it; even if it is the pilot that was shot down, they've probably either gone native or developed Stockholm Syndrome by now.
 * 3) If you are the kind of aliens who prefer to seed planets with The Virus rather than land and conquer, when you do follow up in person, don't just assume that your virus worked perfectly and come without any kind of defenses.
 * 4) Don't try to break up the inevitable La Résistance with heavy handed police state tactics. Ignore them—if your Masquerade is good enough, nobody will believe them.
 * 5) Don't commit your entire force to the first wave. Keep reserves, including your high command, at a safe distance. If the natives are pushovers, you haven't lost anything. If they're tougher than expected, you've got The Cavalry to turn the tide. If they find an Achilles' Heel, the second wave can figure out how to counter it. If all else fails, you've got a way to retreat.
 * 6) Recall that a planet is not a city, and thus any attempt to conquer one is roughly equivalent to a world war and not a small battle, and that planets, unlike cities, can be and usually are entirely self-sufficient. Make sure that you have either sufficient technological superiority/firepower to render any of the natives' numerical and logistical advantages useless, or get yourself a billion-soldier army, a million-man planning department, and get ready for several years of potentially fruitless hard slog.

Corollary: Congratulations! You've just destroyed the defending fleet in orbit around the planet! One problem: there's still the planet itself. Remember this military maxim: "You can bomb it, you can strafe it, you can cover it with poison, you can turn it into glass, but you don't own it unless your infantry's on it and the other guy's isn't." In other words, despite your victory in the void, you probably don't have a single boot on the ground; the planet is thus still entirely in the hands of your enemy, and therefore not conquered and still hostile. Now you have do decide: Do you even want the planet? If so, do you have to keep the surface intact and the natives alive? If you think that the answer is "yes" to either question, see immediately above. Is it worth it given the cost? (Don't succumb to the Sunk Cost Fallacy!) If you don't want it or if the cost is too high, just bombard it from space before the locals send their stockpile of ICBMs your way.
 * 1) Make sure you didn't wake up other alien groups while duking it out or provoke feint attacks. If the planet is capable of supporting carbon lifeforms, there's the potential of precursor civilizations coming and starting a two-way war with you.
 * 2) If your goal is to take over the natives' bodies to use as your own, then your entire invading force is Moles. You are in the perfect position to conquer without anyone even knowing you're there until it's too late; overt acts of conquest, however, Esplin 9466-alpha, will just alert the natives to your presence and get them to mount a defense/resistance. On the other hand, you're in an ideal situation to use a sufficiently xenophobic and violent host species to do the dirty work of eliminating your interstellar enemies for you.
 * 3) Remember that hackers may break into your computers and destroy them with a Computer Virus. Sometimes it's because because their technology was reverse engineered from yours, and sometimes... well, sometimes they just get lucky.

Phase Four: Ruling the Locals

 * 1) Once you've conquered your planet of choice, begin reading up on the proper governing documents.
 * 2) If you do end up having to fight La Résistance, consider using your advanced technology to build some decent, reliable ranged weapons. Hand to hand combat is so last century, and the natives will probably outnumber you. Exception: If shield technology has developed in such a manner that only slow objects can penetrate them, guns are, of course, useless, and you may freely ignore the above advice. However, should there be situations where the enemy is not using/cannot use shields, be sure to have ranged weapons in reserve.
 * 3) For Xenu's sake, if you have conquered the populace, don't take one of your enslaved locals to a preserved library full of technical manuals, scientific journals, treatises on military history, and inspiring historical documents, just so you can gloat about how none of it will help them. They always seem to stumble upon their version of the Declaration of Independence, and then you might as well just bring out the white flag.
 * 4) If you keep any of the locals alive, don't tell them anything about you, or especially your technology. Even if it's for one of your zany schemes, or you feel like gloating, or if you plan on killing them afterward. There's just too much potential for things to go wrong.
 * 5) For that matter, don't take the aboriginals as slaves or pets. They may look cute and/or harmless, but it's just not safe in the long run. On the other hand, providing good living conditions, health care, and good pay (in currency worthless to you) can work quite well so long as your own people don't have obviously superior living conditions. As slaves, aboriginals are nothing but trouble. As valued employees (or so they think), aboriginals may prove surprisingly useful.
 * 6) Pay attention to your conquered territory. If you're not going to administer it yourself, at least garrison it with your own people. Assigning one set of slaves to keep an eye on another is just asking for trouble.
 * 7) Keep a close eye on any turncoats that have joined your side. If they're willing to betray their own species, their words of loyalty aren't worth squat; reward them appropriately. And some of them aren't really working for you at all.

Corollary: On the other hand, don't entirely distrust your turncoat lackeys. They can be used to mask your rule with a "local" face. The more you keep the same under your rule as when the planet was independent, the less the locals will even notice that you're there, and the more likely they'll dismiss La Résistance as paranoid lunatics.
 * 1) While brutal dictatorship is the most obvious and well-tested method of governing an occupied planet, have you considered unlimited freedom to indulge in consumption, booze, drugs, sex, food, gewgaws, games, idiotic music, and other forms of entertainment? (Internet access is particularly good for this purpose.) While possibly more expensive than the alternative (on the other hand, perhaps not—guns, Secret Police, and torture chambers can be awfully expensive), it will pay off by utterly pacifying the populace, who will be so busy buying, eating, drinking, playing, and fucking that the few people who might have the will to stand up against your regime will be a couple of scattered, self-righteous egghead intellectuals. If you play your cards right, even they will be at a loss at how to overthrow you, consoling themselves with simply being unhappy as a small act of rebellion.
 * 2) Use quislings well. They work great for putting a native face on your policies, and sentients take orders better from their own kind. Some native will be willing to help the occupation for luxury for their family and very little real power.

Phase Five: Worst-Case Scenarios

 * 1) If you are not really strong enough to conquer the planet, but are instead faking superiority in order to hide a Weaksauce Weakness or Achilles' Heel, have a plan for the natives figuring this out. Even if it involves begging for mercy, it's better than dying. Who knows, they might even help you willingly.
 * 2) If there's a stronger alien race out there that you're fleeing from because they are even nastier than you, V|don't go out of your way to antagonize the natives if there's any chance they could help you.
 * 3) If there's a stronger alien race out there that you're fleeing from because they are hunting you down for the planet-looting vermin that you are, finish your work quickly before they show up and recruit the natives to their side. Don't count on your Propaganda Machine working.
 * If, despite all your preparation and technology, you're losing the invasion, be sure to wipe your starmaps. The last thing you want to do is give those little bastards directions to your homeworld so they can launch a punitive invasion.
 * 1) Above all, Know When to Fold'Em. Know when to walk away. Know when to run. Sometimes, it's just not worth it.
 * 2) Also, keep this in mind. If your ship's sensors do a scan of the planet's surface and detect a small, blue box innocently sitting there, then the only option is to turn tail and run. Run like an angry god is chasing you... because, frankly, one is. (Sure, there's lots of non-Tardis Police boxes. Can you afford the consequences of not identifying the one you have to worry about?)

Exception: If you can trick the governments of the world into doing something horrific enough to cause this guardian to turn away in shame, you only need to deal with some Welsh bisexuals. Still an unpleasant fight, but it's better odds. Likewise, if your surveillance of the planet below reveals a long history of giant robots, then don't even waste your time, because there is no way this will end well for you.

Corrollary: Run constant sweeps for any and all potential threats at all times; nothing is more embarrassing than someone you know can and will wipe your forces to a man showing up because you only swept for threats on arrival. Things to watch out for include mecha sporting Cool Shades, saucer-shaped cruisers, the Men in Black, starships with ring-shaped FTL systems, Samus Aran, the Spartans and Powered Armor-wearing bespectacled physicists with crowbars - any one of those (especially the last ones) showing up are very prone to wrecking your shit beyond your ability to contain.
 * 1) In case of complete rout and really serious worst case scenarios, make sure you have a Death Star on hand or have bought a planet buster from a friendly empire. Sometimes you just have to cut your losses, accept that you can never conquer Earth, and just blow it up. Of course, watch out for small groups of plucky heroes in or out of spaceships - because those guys will always manage to blow up your Big Death Thing.
 * 2) If the planet you plan to invade is called Terra and populated by a race called humans, reconsider your plans. Humans are incurably violent, exceedingly fond of warfare, and have spent thousands of years dealing with other humans who are a far more formidable foe then all your wussy, over-refined, so-called soldiers. A better idea is to hire humans as mercenaries to conquer other planets. This way your empire will increase in size even more and humans will find pleasant employment in wanton slaughter. Everyone will be happy.

If you follow this policy, be sure you treat your humans nicely. Otherwise they kinda have a habit of rebelling and overthrowing empires in massive interstellar war, whereupon they set themselves up as rulers of their own empire. Nonetheless, if you treat humans well and give them favor and the like, they'll usually become a very important part of your empire's cohesivity. Uuuuuuuusually..

If instead you want to destroy the place, go to Why You Should Destroy the Planet Earth.