For as long as there have been soldiers, there's been bitching about being a soldiers. Soldiers, specifically lower enlisted, gripe mercilessly about everything. Although their leadership might find it annoying, it is, in fact, an important barometer of morale. If your soldiers ever stop whining, something has gone very, very wrong.
One of the most popular topics of discussion in bitch sessions will perpetually be places to fight. Depending on the era you served in and the wars you fought in, your picks for worst places to fight will range from trenches to jungles to desert to caves. There are cases to be made for each of those, and plenty more besides, but one of the worst places to fight in everyone's estimation is a city.
Fighting in a city is its own special kind of hell. There are literally hundreds of places for snipers to hide, and you can bet your sweet ass that at least a few of them are occupied. Lines of sight go from hundreds of meters to nothing in an instant. Navigation can be a pain in the ass, especially in older cities that weren't the subject of any sort of central planning. Unless the city is completely evacuated prior to the fight (an extremely rare occurrence), you've got to worry about the possibility of civilians getting in the way, or worse, taking up arms.
In short, urban warfare purely sucks.
For today's lecture, we're going to take an abbreviated look at both sides of the equation: attacking and defending a city. Please note that this is far from comprehensive. I would not at all be surprised to find out there are people who have written multiple books on the matter, and there's no way in hell I can cover that all in a single post. All I'm trying to do is give you some general ideas to work into RP.
Attacking
So what's a commander supposed to do if they've got to attack a city?
Well, if at all possible, bomb the place to bedrock and call it a day. I mean, damn. If you're a bad guy faction and you're not terribly worried about public opinion, that should never not be on the table. The advantage will always be with the defender in urban warfare, even if all you've got is a handful of teenagers with bolt action rifles. If you don't need the city intact, blow the karker up and call it a day.
If you do need the city intact, well, things are about to get complicated.
Your first step should always be to collect intelligence. That's easier said than done sometimes, but not doing so is tantamount to suicide.
If you've only got a few hours to plan before you have to step off, collect the best maps you can possibly get your hands on. Overhead imagery from your own satellites or probe droids is best. A bird's eye view won't tell you everything, but with it, you can plan routes, staging areas, and other important facets of an operation. If that's not an option, try to get your hand on maps meant for tourists. They can be surprisingly detailed, and while they might not include the latest and greatest in terms of fixed defenses, an intelligent planner can make enough intelligent guesses that you're not going in completely blind.
If you've got a bit more time and the resources to do so, see what you can turn up in terms of HUMINT and SIGINT.
HUMINT, or Human Intelligence, refers to the process of collecting intel from people. This can include everything from interrogating prisoners to reaching out to the locals to dig up any and all possible dirt to be found. HUMINT collection can be a slow and painstaking process. Unless you can verify a piece of intel from multiple sources, you should never, under any circumstances, take it at face value. Some sources are more reliable than others, but even a trusted source could be trying to build rapport in the hopes of feeding you crap at the worst possible moment, and even if they're not, they can still make mistakes.
SIGINT, or Signals Intelligence, is the process of collecting data by intercepting the enemy's signals. This can come from a variety of sources, but for our purposes, we'll break it down into Communications Intelligence (COMINT), which are signals used for communication and Electronic Intelligence (ELINT), or electronic signals not used in communication.
COMINT is at once the easiest and the hardest part of SIGINT. Easiest, because any sort of radio broadcast is detectable so long as it's within range of the right equipment, and hardest, because most of the important stuff is going to be encrypted. Unless you're willing to put a great deal of effort into cryptoanalysis, trying to RP that you've sliced the enemy's comms is a bad idea. There are quicker ways to get a report filed on your ass, but not many. That said, even if you don't have the means to crack their codes, you can tell a surprising amount just by the amount of traffic they're generating. This is called traffic analysis, and when used correctly, it can give you a decent idea of what you're up against. If you can get a probe droid over the city with an antenna to collect data for a few hours, you can effectively locate all of your major centers of broadcast. Filter out the extra noise and while you might not know what the enemy is saying it, you'll know where they're saying it, and that's almost as good.
ELINT collection can be tricky. If you're trying to get a feel for a defensive network, it's not all that hard to pick up active sensors such as radars, but in a city, things are a lot trickier. You're basically looking for anything that's radiating into the EM spectrum and matching those emissions against a database of known enemy equipment. While that might light up fixed anti-aircraft sites, sensor stations, and stuff like that, you can protect yourself against ELINT analysis simply by moving stuff around and keeping a rotating sensor watch. Some positions might be given away, but others might not be. If you guess wrong, you could be looking down the barrels of a half dozen extra turbolaser emplacements, and that's not even taking into account shoulder launched missiles and stuff.
Bottom line to all of this is, before you go in, you want to build up as comprehensive a picture as possible of the enemy forces you're likely to encounter. You're not going to get everything right, no matter how good you are, so the goal is to be as flexible as possible in your planning and take that into account.
Once you've got your intel, it's time to start planning your assault.
First and foremost, you need to worry about neutralizing the enemy. That's where intel is key, because you need to have a good idea of what you're up against if you plan on winning.
As a general rule of thumb, it's a good idea to bring three troops for every one enemy you expect to encounter. If you're fighting in a city, especially a large city, you're going to want the extra bodies. You might note that this can get out of hand really quickly. In a large city such as NYC, troop counts can quickly jump into the millions, and that's not always practical.
If you can't overmatch your enemy, think long and hard about how badly you need that city in the first place. If you can't bomb it to ash, can you blockade it? If you can't blockade it, can you go around without that biting you on the ass? Unless you have absolutely no other choice, do not try to invade a city if you don't have enough manpower.
In the second invasion of Iraq, there were instances of lightly armed convoys of soldiers and Marines assaulting through cities in unarmored HUMVEEs. The fact that they got away with it is nothing short of miraculous. Do not assume that you can pull that off yourself.
If you do have enough troops, you want to do everything in your power to make life as easy as possible for them before they ever set foot in the city.
By now, the phrase "shock and awe" is fairly well ingrained into the public lexicon. For those who aren't, it refers to the strategy of using overwhelming firepower and massive displays of force to degrade the enemy's fighting capability, and was first really popularized by the second invasion of Iraq. To make a long story short, in the leadup to the 2003 invasion of Iraq, Coalition forces bombed the everloving hell out of the Iraqis, targeting key leaders and infrastructure in hopes that the damage, both physical and psychological, would break their fighting spirit.
Whether or not it actually worked is up for debate, but you know what? Screw it. If you have to fight in a city, you want every advantage you can get. Bombing defensive positions, key infrastructure, governmental facilities, and so on might not be as satisfying as dropping a nuke on the place and calling it a day, but if you've got the equipment to spare, you might as well use it. Worst case scenario, you soften the enemy up a bit before sending in the troops.
When it comes time to send in the troops, you want to have clear objectives in mind. Go here, destroy this enemy unit or secure this position. Everyone should know where they're going before they ever enter the city. Keep routes as simple and easy to follow. I'd say avoid places that could easily be used for ambush, but the whole city qualifies under that, so you've already screwed up there. Still, not all ambush sites are created equal, so watch out for especially risky places, particularly anywhere that could be used as a choke point to trap and eliminate your troops.
If at all possible, you'll want armor to be the tip of your spear. In a city, an infantryman is just a target. A tank, on the other hand, is a bull in a china shop. Use the bull. Become one with the bull. Ram its horns up the ass of anyone who tries to stand in your way.
You will need boots on the ground, especially for clearing buildings, but if at all possible, no one should be marching in the open. Use APCs to get them where they're going. If you don't have enough APCs, use lightweight, fast vehicles and make sure they've got as many guns as possible sticking out in every direction. There's no such thing as a perfect solution, but use your imagination and try to reduce the risk to your infantry as much as possible.
When it comes to clearing buildings, keep in mind that, especially in a large city, you will never in a hundred years be able to clear every single one. Pick your targets wisely. If you're catching hell from a particular building, blow the damn thing up. Speed and aggression are key, and if you get bogged down trying to pussyfoot around with the enemy, they will eat you alive.
If at this point, you've accomplished your objectives and defeated the enemy, congratulations! Now you've got a whole different mess of problems to worry about, but that's something for another time.
But what if things aren't going so well? What if you've secured some of your objectives, but others are giving you trouble?
For that, we've got a handy guide.
Can you bomb it?
  • Yes- Bomb it.
  • No--->
  • Can you throw bodies at it?
  • Yes- Throw bodies at it.
  • No--->
  • How badly do you need it?
  • Not all that much, really- Leave it alone.
  • Quite badly--->
  • Can you hold what you've got until more assets free up?
  • Yes- Hold what you've got until more assets free up
  • No--->
  • Sucks to be you.
If you've done your job right, you will have reserve forces on hand for just such an occasion. After all, the only thing you can truly count on in warfare is for something to go pear shaped at the worst possible moment, so you should always take that into account. Have several Quick Reaction Forces, or QRFs, onhand to rapidly respond to any problem that presents itself. Also, once your main force begins completing its objectives, don't be afraid to free up troops from less critical areas and have them respond to crises as they present themselves.
So what if you've done everything you can, but you just can't complete your objectives without losing your entire force?
Retreat and bomb that sucker down to bedrock. At least now you can say you've tried.
Defending
Defending a city is loads easier than attacking it. For starters, you already know the place, and it really doesn't matter what the enemy brings to bear, because if you're in charge of holding it, you've got what you've got and that's all you can really count on. Even if you've got spot on intelligence as to their troop counts, it really doesn't do you much good. As the great philosopher Ron White once said:
I don't know how many of them it would have taken to whip my ass, but I knew how many they were going to use.
That man is my spirit animal.

Anyway.
You're going to need to accept a few things right from the start.
  1. It may not be possible to hold the city. Holding one isn't impossible, and it's actually a lot easier than attacking it, but if they're determined enough and have enough bodies to get the job done, you're screwed. With that in mind, make sure you have an evacuation plan. Ideally, you'll establish a set point, either when you've taken a certain amount of losses or when they've captured a certain number of critical objectives, and once you hit that point, retreat.
  2. The entire city is your playground. Obviously, you'll want to keep as much of it intact as possible, but don't be afraid to use the abundance of resources at your disposal. Drop buildings to cut off the easiest routes and to create makeshift fortifications. Have a fireteam on every floor of every building you possibly can. Go freaking nuts.
  3. Time is on your side. In an invasion, big cities are high value targets. Even if you can't successfully hold yours, the longer you can make them fight for it, the more you can make them bleed for it, and that makes life a little easier for everyone else.
When planning the defense of a city, your biggest threat comes not from the ground, but from the air. Orbital bombardment, air dropped ordinance, and artillery are all huge threats. In the world of Star Wars, these can be easily countered by throwing up a shield, but it's a good idea to have standard anti-air assets in place.

If you read the portion on attacking, you know the enemy is going to try to collect intel on you, so your defense should be built to be flexible. Try not to rely overmuch on things like fixed turbolasers or SAMs. Teams of specialized troops with shoulder fired missiles can be extremely effective against aircraft, and if you've got a large city, there's no shortage of places to put them. Aircraft are expensive, so if the enemy starts losing enough of them, they will be reluctant to send them in.
Artillery fire is harder to defend against, but the beautiful thing about a city is that it's damnably difficult to rely on indirect fire when you've got skyscrapers to contend with. That's not to say that your command and control center shouldn't be deep underground with as much concrete and steel between it and any potential projectiles as possible, but you can breathe a little easier knowing that the redlegs will have trouble targeting your ass.
The same problem applies to orbital bombardment, but to a lesser extent. Unless the enemy can be assured of space superiority, they're not going to be able to get a capital ship directly overhead, and angled fire is far less effective. If they do control orbit, well, you're screwed anyway. Might as well hang it up and hope POW food doesn't taste too terrible.
In every city, there will be key locations that have to be protected. Your average city becomes a dystopian wasteland once you kill power, and even more so if you manage to kill the water and sewage pumps. Without fresh water, people begin dying in a matter of days, and without a means to get rid of sewage, well, use your imagination. If an attacking force manages to gain control of the utilities, they can effectively force the civilian population to surrender. And, I hate to say it, but even the most patriotic of civilians is going to start looking at you as a problem to be eliminated if they can't flush their toilets.
Other important sites include, but are not limited to, local governmental facilities, food storage, medical centers, and of course military installations. If enough of those get captured and you can't take them back, it's time to pull out. It sucks, but it's better for everyone that way.
Fortunately, there are a number of ways to prevent them from being captured in the first place.
The easiest and most cost effective method is to limit the enemy's mobility. Stalingrad situations where both sides refuse to budge and they're willing to throw as many bodies as possible at the problem are rare. In modern maneuver warfare, speed is the key to success, and attackers rarely have the time and manpower to waste on a single city.
Tanks are marvelous creations, capable of tackling the toughest terrain with little difficulty, but even they have their limits. Crater your most accessible avenues of approach. If you've got mines and you can reliably clean them up after, go nuts. Send out sappers to weaken bridges and roadways so that heavy armor can't pass. You can drop whole skyscrapers across roads if you have to, blocking the enemy from maneuvering while leaving your forces free to go wherever on the other side. Or, hell, rig buildings to blow and drop them once the enemy is past, cutting off their escape route.
If you can limit the enemy's ability to use vehicles, they'll have to rely on foot soldiers, and that's where the fun really begins.
Every building with exterior windows is a potential ambush site. If you place a platoon, or even a squad or a fireteam, on the second or third floors of as many buildings as possible, you've created a nightmare for invading troops on foot. It's a lot easier to shoot down than up, and you can focus fire from multiple directions while they're still trying to figure out where it's coming from. Overconfidence can still get you killed, but the analogy of shooting fish in a barrel comes to mind.
Their only choice is to try and capture a building to get some sort of cover, and, much like the city itself, it's a lot easier to hold a building than capture it. Sheer weight of numbers might win in the end, but it won't be an easy fight, and it sure as hell won't be a quick one.
Even if you can't hold the city and have to withdraw, there's nothing that says you can't leave some troops behind to harass them for weeks and months to come. If you've got something like the US Special Forces, you can leave teams of highly trained specialists behind to snipe and harass the enemy, making life miserable for them. The more you annoy them, the greater the chances of reprisals, and the harsher the reprisals, the easier it is to convince the locals to fight back.
In the span of a few weeks, a great military victory can turn into a prolonged and bloody insurgency, and one the enemy has no chance of defeating. After a certain point, it becomes self sustaining, and you barely have to lift a finger.
For more on that, see the Asymmetric Warfare post.
So there you have it, folks. I'm tired as hell so I'm sure I missed something, so if there's anything you can think of feel free to sound off in the comments. Just don't be an ass.