This is just a quick guide on how to play with Mongolia. In my Civ4 experience, they are the most powerful Civ, and this guide will detail why and how they can dominate the early game. Any feedback or comments are welcome.
Starting out: 2 choices for your leader. The great Ghengis Khan and Kublai Khan.
Both civs are aggressive, so the choice here is Culture or Expansive. I would recommend Kublai for difficulty of prince or lower. And the great Ghengis for higher difficulty and larger maps. But both are great choices. Generally because of Kublai's culture advantage, he will be more likely to get you a higher score. But Ghengis can get cities to very high population levels, up to 12-14, thus creating very high production and income levels. For beginners Kublai is your best bet, and for more seasoned players, look to Ghengis for your glory.
Your capital. Kharakorum. When placing your capital if possible starting on a square of Hills/Plains is a good idea, for the extra shield it produces can give you a quick production boost. However any capital placement is fine. Your starting research should revolve around what bonus squares your capital is looking at. In most cases, religion will not be needed, as you will see later. I recommend going for animal husbandry especially if you have any pigs or cattle or sheep, but more importantly to show horses on the map as they will be the only resource you need to secure. After that make sure to get archery soon.
1 or 2 scouts should be your first build as early scouting is key for this game. You start with one, so do your best to pop a few huts early. These can give you a nice gold coffer to get you set up for the early war you will be waging soon. Get out and scout as effectively as possible and find your neighbors, in particular discover the location of their capital cities. Avoid bears, and panthers. Sit on hills and forest to end your turns so they have the best chance to survive, obviously. Depending on your food supply, build a worker after the scouts if your population is up to 3. If it is still at two, get a warrior or archer built and then a worker.
The early worker is key in all games I think, but particularly in this game. Have the worker put up improvements on your bonus tiles. Once the capital has some nice tiles to work with, look to expand to the horses. Now if horses are nowhere to be found, then you're looking at a tough game to run although Mongolia being aggresive can still become powerful. Mongolia depends on horses like Rome does on Iron. But most maps have abundant horse tiles and you should be able to find them easily if you did your scouting.
After that first worker is built, you will need that defender unit if you did not build one before the worker, if you did, start a settler. Your first city expansion should be in the direction of the horses. The placement of your 1st expansion city should be in as close to horses as possible while also being as close to you're capital as possible. I recommend going about 4-6 squares from your capital. You need low corruption but also to make early infrastructure more manageable. This is optional and subjective so the only key here is to get the horses hooked up as early as possible. If you have horses in your capital borders (lucky you) then look to just get your first expansion where you can build a lot of production and food, as you would usually do. Bring that 1st defender unit to the new city. Build a new defender for your capital.
2 Cities. Horses hooked up or on the way. After the 2nd defender unit is built in your capital, time for your last settler. Yes your last settler. Before that, what is your science doing? Well, your choice here is bronze working or horseback ridding. I usually go for the bronze first, as you will want to see those copper squares, and start to do some forest cutting. After bronze working, you have to go for horseback ridding, it is your most important technology in this game. Once the 2nd(last) settler is built (chop a forest down if your worker is available to pop that 2nd settler really fast.) Look to the opposite direction of your 1st expansion for your 2nd expansion. This will give you a nice land base, and make for easily manageable empire. Bring the 2nd defender to your 2nd expansion and build a new defender in your capital. Build barracks in all 3 of your cities after that. Once your expansion cities have a population of 3, pump out a worker from each of them. I don't like to automate workers, but if you're really lazy as long as your horses are hooked up you should be ok. But they will build farms and you need mines. So, don't be lazy and start those workers building mines on every possible hills in your workable land area. Production is the key, so get those mines up a.s.a.p. Also get an archer on those horses.
Your empire should look like this:
3 Cities
3 workers building mines
3 defenders fortified in your cities
3 barracks - 1 for each city
Horses hooked up and gaurded
A well scouted picture of the civilizations that will soon crumble under your feet
Insert Ghengis Khan and Kublai Khan evil laugh here.
Your 3 cities now should simply cue up one of the best UU in the game(IMO)
Mass build Keshik units in all 3 cities. Put them on repeat build so you never waste shields. Use the forests of your empire to quickly pump out as many Keshiks as possible. Upgrade them all with retreat/withdrawal upgrades. Depending on the amount of hills you mined and forest available, you should have a force of 16 - 20 within a fairly short amount of time. Your 3 cities should be pumping them out at about 4-6 turns apiece. If you use your workers to cut down forests, you can get thise type of force in about 12 -15 turns.
Depending on how aggressive you want to play, you have some options at this time. Your neighbors should be starting to creep up on your borders at this time. Don't worry this is good. Wait for a rival civ to get a city to pop 2, then just take that city from them. I recommend using the Keshik unit a.s.a.p so take your first 4 -5 and go mess with your most powerful neighbor. At this point in the game a straight out attack is not out of the question, as his capital will likely only have a handful of archers, and you could probably roll over their capital city easily enough. When you take their capital city, if it is close to your capital (Kharakorum), keep the city. If not then burn it to the ground.
If you don't want to gambit on your first little army, take out all his resources. Main thing here is to get the Iron and the Copper and pillage the mines and the roads leading there. In most cases and on lower difficulties, you might even beat them to that iron/copper. Keshiks are the best pillage unit in the game, up till gun ships, (IMO) since they suffer no movement penalty ever. Forest, jungle, hills, whatever the case they always get 2 movements. Look to pick off archers and warriors on open squares if they send any out of their cities. If possible, upgrade one your Keshiks to medic, and try to keep that unit out of harms way.
How you run your war effort is completely up to you. Basically, this army can easily over run any civ on your cotenant easily and quickly, while taking very few losses. The movement of these units allows you to wage war on Civs nearby or fairly far away. They also make for amazing scouts especially when you are at war or have open borders with a civ. They can quickly map out most of the land on the map, drop a couple off in a galley and they should have most of any new land mass mapped out quickly, with very little danger from barbs. Also very easy for 1-2 of them to raze an early barb city to get them upgraded. Very versatile units that offer many tactics all centering on the mobility of the unit. Pillage, Pillage, Pillage. These units can pillage and move in the same turn regardless of terrain. A civ with no resources or square improvements cannot do much.
Try to avoid attacking a city built on hills. This is why the capital sack is so easy with Mongolia. You can easily get to their capital quickly and the capital is less likely to be placed on top of a hill. In the early game if you sack a rivals capital they will do anything to make peace with you and you can basically leave them alone from that point on since they will offer very little challenge to you in the future. Leave them alive and demand tribute. Or just roll over them when you decide their end is at hand. You do not need to actually eliminate a Civ to take them out of contention. They key to all your efforts will be to simply not allow civs to have iron or copper. Spearmen can cause serious pain to your Keshiks. Although 2 will kill 1, its not good math for a war effort and you should avoid spearmen at all costs. They cant chase you. Just move your attention to new targets. Sneak up on them. Bring your armys towards them from directions unexpected. TIP: You don’t need to finish a Civ off. If they have 1 or 2 cities left with Spearmen hold up. Just end the war with them and move on to the next Civ. They wont be difficult to finish off later with Axemen/Swordsmen/Catipults.
The bottom line is while Archers are the primary defenders in Cities, your Kashiks can easily roll over those cities. Once Longbows start to pop up, your UU will no longer be able to actually take cities very easily, but you still have the best Pillage unit in the game.
This is just one way to use Mongolia and get the most out of their UU in the early ages. For all those who might have doubted Mongolia, or the Kashik, try this tactic and see how it works for you.
Feel free to post questions and comments.