Note: This guide assumes you have all game-altering DLC and expansion packs (all Civ packs, Wonders of the Ancient World, Gods & Kings and Brave New World)



Siam's - or Thailand's - history is that of skillful diplomacy in the face of external threats, and the understanding that the largest nations are not necessarily the most powerful. Established in the aftermath of the fall of the Khmer Empire in the 13th century, the first Thai kingdom, Sukhothai, would grow rapidly to become a major regional power, using trade and alliances to strengthen their position rather than through excessive costly conquests. Another Siamese kingdom, Ayutthaya, would overshadow Sukhothai and become an even more powerful and wealthy nation.

In the 18th century, however, neighbouring Burma in the west would invade and conquer Ayutthaya, only to withdraw three years later to fight a war with the Chinese to the north. Yet Siam would recover surprisingly rapidly. A growing threat from European colonisation would be seen off by exploiting the rivalry between Britain and France; while Siam would lose a significant amount of land, they were the only nation in Southeast Asia to avoid being taken over by European forces. But they were not free from their influence; a revolution in the 1930s led to a constitution and the end of absolute monarchy, which was followed by a succession of military coups, brief periods of democracy and relative instability. Despite strong economic growth, tourism and improvements in living standards, Thailand is now yet again plunged into a political crisis. Your task now is to build a stable nation; to build a civilization that can stand the test of time.



Before I go into depth with this guide, here's an explanation of some terminology I'll be using throughout for the sake of newer players.

Beelining - Focusing on obtaining a technology early by only researching technologies needed to research it and no others. For example, to beeline Bronze Working, you'd research Mining and Bronze Working and nothing else until Bronze Working was finished.
Finisher - The bonus for completing a Social Policy tree (e.g. Free Great Person for Liberty.)
GWAM - Great Writers, Artists and Musicians. These are the three types of Great People who can make Great Works, a major source of tourism for cultural Civs.
Opener - The bonus for unlocking a Social Policy tree (e.g. +1 culture for every city for Liberty's opener)
Tall Empire - A low number of cities with a high population each. Your UA encourages going down this route, and your UU's speed is less of a disadvantage in a tall empire.
UA - Unique Ability - the unique thing a Civilization has which doesn't need to be built.
UB - Unique Building - A replacement for a normal building that can only be built and used by one Civilization.
UU - Unique Unit - A replacement for a normal unit that can only be built by one Civilization or provided by militaristic City-States when allied.
Uniques - Collective name for Unique Abilities, Units, Buildings, Tile Improvements and Great People
Wide Empire - A high number of cities with a low population each.
XP - Experience Points - Get enough and you'll level up your unit, giving you the ability to heal your unit or get a promotion.

Siam is biased to avoid forest. Forest-heavy areas tend to be towards the poles, so this is likely to push you towards the equator, and maybe even a jungle starting position to go nicely with your Wats. Otherwise, you're likely to be surrounded by more open land than most other Civs, helping you explore and discover City-States in those earliest turns.


The Siamese unique ability encourages City-State friendships throughout the game, while both their unique building and unique unit come in the medieval era for a strong midgame.

• Cultural, maritime and religious City-States gift 50% more culture, food and faith respectively when befriended or allied
  
• Unit gifts from militaristic City-States start with 10 more experience than normal
  
• Mercantile City-States are not affected.

A mounted melee unit

*Assumes a normal speed game.
**Upgrading requires 1 Horse resource.


Negative changes

• 3 moves, down from 4 (-25%)

Positive changes

• 25 strength, up from 20 (+25%)
  
• Does not require Horse resources
  
• 50% bonus vs. mounted units

Building of the Science line

*Assumes a normal speed game.


Positive changes

• 3 culture generated per turn

Note that these scores are a matter of personal opinion based on experiences with the Civilization. You may discover a way of utilising the Civ more effectively in unconventional ways.

Cultural: 5/10
Diplomatic: 7/10
Domination: 6/10
Scientific: 8/10

Despite all the dealings with City-States you'll make, diplomacy isn't necessarily your best route as you have absolutely no bonuses to gaining City-State influence. Siam has no real advantages to cultural victory, despite bonuses to culture generation, as both Siam's unique sources (from the UA and the Wat) don't affect tourism gain. While the UU can give you an advantage in midgame warmongering, it's mainly a defensive unit.

So, that leaves science. As technology costs go up the more cities you have, generally tall empires have an edge with it. Siam's food bonus from maritime City-States encourages tall-building, and the two cultural advantages (involving both the Wat and Cultured City-States) work best for tall empires, as Social Policy costs also rise with the number of cities.


Overall

Siam's playstyle is unique, but elements of it are shared with other Civs. Sweden is another Civ that builds tall yet makes good use of City-State interactions, while the Aztecs and the Inca have strong food bonuses which helps them out at scientific victories. The Netherlands can potentially persue this route, but this is dependent on having good floodplain-heavy lands.

Same start bias

No other Civ just has the "avoid forest" bias, although both Egypt and the Huns have it in addition to avoiding jungle. Avoiding forest increases your odds of starting away from tundra/temperate regions hence making you more likely to start nearer the equator. Arabia and Morocco have desert start biases, and the Aztecs and Brazil have jungle start biases that have somewhat similar outcomes, as does the "avoid tundra" start bias of Assyria, Babylon and the Songhai.

Similar to the UA

Extra bonuses from City-State friendships and alliances is something unique to Siam, but an encouragement to hold long-term alliances is shared with Greece. Greece is a diplomatic Civ first and foremost, but differs from others by lacking bonuses to gaining influence - much like how Siam doesn't have any bonuses to City-State influence.

The faith bonuses make Siam one of the few tall-building Civs that can still effectively start a religion. Ehiopia's Stele can also be used in such a manner, as can Sweden's UA (using the Warrior Code Social Policy, Sweden can get an early Great General and gift it to a religious City-State for an instant alliance.)

Food bonuses, again, can also be found as features of the Aztecs, Incas and Netherlands.

Similar to Naresuan's Elephant

Other uniques that replace Knights include Arabia's Camel Archers, Mongolia's Keshiks, Songhai's Mandekalu Cavalry and Spain's Conquistadors, but Naresuan's Elephants don't really function like any of those.

Instead, a good comparison can be made with Spain's Tercios. Both units have a similar level of strength and a strong bonus against mounted units essentially making them early, cheap and resourceless (but slow) Lancers. Naresuan's Elephants lack defensive bonuses, but are faster than Tercios.

Similar to Wats

The only other UB with a direct bonus to culture compared to the generic building is Songhai's Mud Pyramid Mosque. It arrives a little earlier than Wats and have the maintenance cost removed, but has a smaller cultural bonus and is a lower-priority building for new cities.

Up to four Wats or Mud Pyramid Mosques can be obtained for free with the Legalism Social Policy from the Tradition tree, and the same applies for the two UBs that replace culture buildings - Ethiopian Steles and Celtic Ceilidh Halls.

Above: Note the 4.5 food to the capital and 1.5 to all other cities, rather than 3 and 1 respectively.

Siam is a Civ which rests heavily on its UA, giving you lots of food, culture and faith if you can befriend lots of City-States, but the challenge is making those friendships and alliances without any bonus to gold or influence gain.

Before going anywhere, you need to know the general victory direction you'll be heading into. I've already stated this a couple of paragraphs ago in the "At a glance" section, but I've got to state it again to be sure. Siam isn't good at cultural victories - it has no bonuses to tourism whatsoever. Naresuan's Elephants may be powerful, but they're weak against cities and their slow speed encourages defensive usage. And you have no advantages to holding City-State alliances. But what you have is more food bonus from maritime City-States, helping to build tall. More culture, which works better in tall empires for getting lots of Social Policies. And as the cost of technologies goes up the more cities you have, Siam works best towards a scientific victory.

Yet this repeated statement doesn't give the whole story, as Siam's emphasis on City-States gives them unusually high flexibility in the end-game. You should always take the Patronage Social Policy tree as Siam to maximise your UA's potential, but it also has the effect of making it easier to hold City-State alliances towards a diplomatic victory if a scientific one seems unlikely to work. So, emphasise science throughout the game, but know that it's not hard to switch to diplomacy if need be.


Right, we've got the eventual victory direction cleared up, now, how to best use your uniques to get you there? Well, to start off, it's hard to buy your way to City-State friendship and alliances in the early-game but luckily, there's plenty of City-State quests avaliable to destroy Barbarian encampments, so all you need to do is spare a few military units.

At first, favour religious City-States so you can secure a Pantheon and hopefully a religion. Religious City-State faith doesn't scale with how many cities you have, (unlike religious buildings and certain faith-boosting beliefs, where the more cities you have, the higher faith potential you have) meaning they will likely be your primary source of faith. You'll want to work towards the Papal Primacy founder belief - together with the Patronage Social Policy tree's Consulates, you can keep City-States in a state of permanent friendship hence providing food, culture and faith without you needing to spend extra gold.


Once you've got a religion going, you can move your primary attention from religious City-States to maritime ones. Due to the lack of Barbarians at this stage of the game, and a relative lack of money free for bribing City-States, it's fairly hard to keep City-State alliances at this point. You can worry about cultural City-States later - for now, Wats will cover that area.

Focusing on food will grow your cities tall and give you plenty of science. Keep a Spy in your capital or your highest science-producing city (your capital tends to be the most likely city to be targeted by Spies) to stop anyone leeching off your tech advantage, and dedicate the rest of them to rigging City-State elections.

The power of Naresuan's Elephants means you can neglect the bottom half of the tech tree for quite some time and focus on working towards the Scientific Theory technology for Public Schools.

In this time, International Trade Routes will eventually become more effective so you'll have more money for broadening the range of City-States you befriend. Few Civs focus so much on having so many City-State allies at this stage of the game, so you can get quite an advantage at the World Congress.


By the time ideologies come along, International Trade Routes will give you a decent economy for maintaining City-State alliances. Favour both cultural and maritime City-States, and be wary of diplomatic Civs which may compete with you for City-State influence. Try to work towards building the spaceship, but if you can't manage that, seize the advantage of picking the Patronage Social Policy tree and try and go diplomatic.


One thing Siam does brilliantly is having some way of dealing with each of the four victory routes, especially cultural Civs.

Wats and extra culture from City-States means you can be the main block to other Civs winning through tourism accumulation. Your UU's strength for its time is good for seeing off mid-game warmongers, or even on the offensive against Civs with a tech advantage. And going into the Patronage Social Policy tree gives you a stronger ability to pull City-States out of the hands of diplomatic Civs than most.

Diplomatic Civs will give you the most trouble, but at least you won't be powerless against them.


Siam appears to get 10 more experience points on unit gifts from militaristic City-States than other Civs. While nice if you're befriending as many City-States as possible, the bonus isn't really significant enough to merit shaping your strategy around it. Religious, cultural and maritime City-States will typically be more worthwhile to befriend and ally.

• Build tall and go for a scientific victory, or diplomatic as backup
  
• Get a few units to kill Barbarians for City-State quests early on
  
• Favour religious City-States until you've got a religion
  
• After getting a religion, favour maritime City-States, and cultural as well once you can afford it
  
• Once Education and Chivalry are researched, beeline Scientific Theory to get more science sooner, as your UU allows you to neglect military technologies at this point.

Wats take a complex building - the University - and adds a simple upside: 3 points of culture. Wats contribute more points of culture than most other buildings, making them excellent for expanding city borders faster or for Social Policy gain, and as you should be building them in all your cities, you can build up a strong defence against cultural Civs.

After getting your Worker technologies out of the way, work towards Education to get Wats as soon as you can, as the sooner you have them, the sooner you can take advantage of the science. The culture's a nice bonus, but the science is the main point.

As already mentioned, Wats come in at a time where holding City-State alliances can be difficult. Barbarians are rarer, but your economy hasn't really taken off yet. The culture from Wats means you can still get an edge to Social Policy gain at this stage of the game without having to spend your money on cultural City-States. Instead, dedicate your money on maritime City-States until International Trade Route gold picks up and you can maintain a wider range of alliances.

Getting lots of culture out of Wats and cultural City-States will be useful for reducing the influence of cultural City-States. Low influence means they won't hurt your happiness as much, but crucially you may be the main barrier to them winning. Be wary of Open Borders agreements and spreading your religion to their cities (or vice versa.) Try to grab the Great Firewall wonder later in the game - it builds on both your cultural and scientific advantages.

• Head towards Education as soon as you're done with Worker techs and any other high-priority technology
  
• Build Wats in all your cities
  
• Be wary of cultural Civs, as you'll be a major barrier to them winning with all that culture.

Essentially an early Lancer, (with the downside of slightly slower speed meaning relatively little on the defensive where roads give you a speed advantage,) Naresuan's Elephants are amazing defensive units for their era, and stay relevant even in the industrial era. Research Chivalry after you're done researching Education for Wats (they're right next to each other in the tech tree) or earlier if you're under threat of being attacked.

Much like Mayan Atlatlists, Naresuan's Elephants allow you to ignore military technologies while you focus on a different route. Rather than researching Longswordsmen, Musketmen and Lancers, you can just keep to the top half of the technology tree to grab Scientific Theory early, and get Public Schools rolling sooner rather than later, which means more science sooner rather than later.

Aside from being able to ignore military technologies, the one-size-fits-all nature of Naresuan's Elephants in the medieval and renaissance eras lets you keep your military small, freeing up money for City-State bribing.


Compared to Lancers, Naresuan's Elephants have these differences:

• 35% cheaper (120 production cost rather than 185)
  
• No need for horses
  
• Avaliable two technology columns earlier (2nd column of medieval era rather than 2nd of renaissance)
  
• 50% bonus vs. mounted units rather than 33% (though the bonus Lancers have keeps on upgrade and they can more easily get Formation II for another 33%)
  
• 25% less movement (3, down from 4)
  
• Different upgrade path

The two units have the same strength at 25, one point higher than a Musketman. Without any promotions, Naresuan's Elephants will beat Lancers in a one-on-one fight, though Lancers can more easily flee.

Generally, the main flaw of Lancers is their short window of usage before becoming a niche Cavalry-counter unit, their horse requirement and their placement on a very military-heavy point on the tech tree. Naresuan's Elephants solve all these problems.


Against mounted units, Pikemen have a strength of 24, which is higher than the Knight's 20. However, against Naresuan's Elephants, Pikemen are still at a disadvantage as their effective strength is one point under that of the Elephants. Pikemen are 25% cheaper to build than Naresuan's Elephants, so watch out in prolonged wars, but generally your Elephants are counterless by non-unique land armies in the medieval and renaissance eras.

But be careful from threats from the sea - for all the army slaying your Elephants can do, they're powerless against naval units. Get a few Crossbowmen, Galleasses, Privateers or Frigates if need be if a Civ with a strong navy's in your game (England, the Netherlands and the Ottomans especially.)

Into the industrial era, Naresuan's Elephants, like Lancers, take on a niche anti-Cavalry role. A good idea is to upgrade some Elephants, and hold off upgrading others until Landships come along. City-State alliances should provide you with all the horses you need for that task.


Typically, Siam works well when building tall and playing defensively, but Naresuan's Elephants' lack of a (non-UU) weakness makes them good at clearing units on the offensive. They're only slightly more effective against cities than Pikemen, but three movement points is still enough to get the final hit from outside the city's attack range. Be sure to bring plenty of siege units if you're going down this route.


None. Keep in mind you need horses to upgrade Naresuan's Elephants to Cavalry, and Landships and onwards will need oil (Giant Death Robots require Uranium, but you probably won't have time to upgrade that far.)

Building tall, interacting with City-States and going for a scientific victory gives you a clear route: Tradition, Patronage and Rationalism. Though you may lack money compared to most Civs aiming to ally lots of City-States, you don't need to go into Commerce - Rationalism will be more worthwhile. You can return to it at the end of the game after everything else if need be for a little extra cash.


Opener

Quickly-expanding borders help ensure you can make the most of a high population, particularly in your capital, which will likely grow taller than any of your other cities.

Oligarchy

In the medieval and renaissance eras, Naresuan's Elephants are such a one-size-fits-all solution that you can keep your military slim. With free unit maintenance for garrisoned units, you can really reap the rewards of the saved cash for buying more City-State favour. Plus, the city ranged strength bonus makes it much harder for enemies to invade your lands.

Legalism

You can theoretically get up to 4 Wats for free using this policy as Wats count as culture buildings for the purposes of this policy, though if you're going down this unconventional route, be sure to build Libraries and all the other cultural buildings avaliable first (typically this means getting an Amphitheatre in every city.) Time it right and you could save yourself production and maintenance (Wats have a higher maintenance cost than all culture buildings except Broadcast Towers.)

Typically, though, you'll want Legalism sooner rather than later due to the power of the Landed Elite and Monarchy policies.

Landed Elite

Your capital will typically become your most populous city (even if you have a relatively low-food start) thanks to maritime City-States, and this policy builds on that. Unlike culture or faith from City-States, food bonuses are affected by modifiers.

Remember that the 10% growth bonus isn't a 10% bonus to food, so if your capital has 20 points of food, half of which is being eaten, a 10% growth bonus will add one point of food, not two.

Monarchy

Gold and happiness for building your city tall. It's quite possible to reach size 30 or even 40 by the end of the game, which gives plenty of gold, which in turn can be boosted even further with a Market, Bank or Stock Exchange.

Aristocracy

The main advantage is the bonus to wonder building, and there's a few decent ones over the course of the game worth grabbing.

Finisher

More growth bonuses! Free Aqueducts! More population points mean more science.


Opener

Keeping alliances and friendships for longer means you can make more out of your UA. The associated wonder, the Forbidden Palace, is fairly easy for Siam to build due to your UU and UB being on the two technologies leading into Banking.

Consulates

A raised resting point makes it easier to reach friendly or allied status with City-States. A pledge to protect on top of Consulates is only 5 influence points below friendship, and use of the Papal Primacy founder belief puts can allow you to achieve permanent friendship.

Philanthropy

And now your gold goes further when bribing City-States. You can't really rely on City-State quests alone to hold long-term City-State alliances, so this policy will really come in handy.

Scholasticism

So, you're keeping long-term alliances for lots of food, faith and culture. But now, these alliances can directly aid science! This is a strong incentive to keep alliances rather than just friendships, but be careful you don't end up competing for influence with a City-State backed by a Civ which can easily afford to "outbid" you with gold donations.

Cultural Diplomacy

While tall empires tend to have less trouble with happiness than wide or conquering ones, that's not to say you're immune to unhappiness troubles. Gifted luxuries from City-States are now worth 6 happiness rather than 4 with this policy. You also get more strategic resources from City-States, which can be useful for upgrading Naresuan's Elephants or suchlike, but typically either City-States will completely lack a strategic resource you need or have more than you'll ever need anyway.

Merchant Confederacy

Works well with the Freedom level three tenet Treaty Organisation for making those influence-gaining Trade Routes more effective, but even if you're not using it, trading with City-States avoids giving away science to Civs who are behind you technology-wise.

Finisher

Free Great People from City-State alliances! It's hard to write a strategy for this, but just enjoy the helpful random boost free Great People offer.


Because of the importance of science, it may be worthwhile finishing the Rationalism tree before diving into tenets. This will vary based on your situation, but the earlier you can get that free technology, typically the more effective it'll be as technologies tend to be faster to research in the end-game than earlier on.

Opener

Maintaining positive happiness isn't particularly difficult for Siam, and Rationalism's opener rewards you with a science boost for it.

Secularism

Your capital in particular will have lots of specialists, which this policy translates into lots of science.

Humanism

Great Scientists are good, no matter how you want to win. The faster you can produce them, the quicker you'll get to those spaceship technologies.

Free Thought

Seeing as you should be putting Wats in all your cities, this policy is more powerful than Rationalism's Opener. Building tall, you might not see much benefit from the science bonus to trading posts, but the Wat boost is still welcome.

Sovereignty

Reducing the maintenance of your science buildings (Wats included - they count as culture buildings and science buildings for purposes of Social Policies) will give you a little more money spare for those City-State alliances. Which gives you science thanks to Scholasticism. Take this policy earlier if you really need the gold.

Scientific Revolution

Due to the focus on City-States, you may not have much gold spare for Research Agreements, but that's not to say you can't make any; they're still a great source of science. And with this policy, they favour you more than the other Civ (unless that Civ has this policy or the Porcelain Tower, but generally you'll make more out of the policy than they will.)

Finisher

A free technology pushes you closer to a scientific victory, or maybe to Globalisation for that backup diplomatic route.

Go with Freedom. It offers both science and diplomacy, as well as bonuses to help support a tall-building empire.

Around this stage, you should be fairly sure which victory route will be the most viable. I'm assuming you're going for a scientific victory, but I'll list substitute policies if you're going down the diplomatic route as well. I'm also assuming you're taking three level one policies, two from level two and one from level three.


Covert Action

Even if you're playing scientifically, you should be able to free up some Spies for City-State rigging. Higher success odds help give you an edge over rival Civs using Spies there, and hence more easily hold key City-State allies.

Avant Garde

Tall cities mean lots of specialists, and hence lots of Great People potential. Adding another bonus makes that Great Person production even better, meaning more last-minute Great Scientists.

Civil Society

And now all those specialists use up half as much food, allowing your cities to grow to incredible heights. Alternatively, if you're going down the science route, you can use all that newly-freed up food to make your cities work more production-intensive tiles instead of food-heavy tiles, ready for building the spaceship.


Universal Suffrage

Got happiness troubles? Not any more, all your specialists will now produce half the unhappiness. Fine with happiness? Golden Ages will be longer, so you can turn your happiness into a boost for gold, production and culture - production will be useful for building the spaceship, while gold is, of course, useful for securing City-State alliances.

New Deal (Scientific Siam favoured)

Any old Academies or Manufactories (or any other Great Tile Improvement for that matter) will now contribute more. Add the multipliers you have in your cities, and that could mean quite a decent boost to science, production or suchlike.

Arsenal of Democracy (Diplomatic Siam favoured)

Keeps you better-defended in the late-game, but also gives you a good way of using your tall cities' production towards diplomatic aims, with more effective unit gifts.


Treaty Organisation

Even when playing scientifically, the Treaty Organisation tenet will often be a strong choice. Not only does it help secure your UA's advantages, but it frees up gold you would be using to buy those City-State alliances in favour of something else, and it also helps slow down other diplomatic Civs' chances.

Space Procurements (Scientific Siam favoured, if there's enough money avaliable)

If you're playing the scientific route and have enough cash avaliable to buy spaceship parts, Space Procurements is an option, but Siam isn't exactly the richest Civ in the game. Only consider this option if you think you can scrape the cash together to buy at least a couple of spaceship parts, otherwise you'll make more out of Treaty Organisation.

To make the most out of Siam, a decent religion will be really useful. Emphasising influence on religious City-States early on will help make sure you don't end up empty-handed, and the extra faith throughout the game will help ensure City-States are of your religion and no-one else's.

City-States sharing your religion have a 25% slower influence decay rate if it's above the equilibrium point, and regain influence 50% faster if it's below the equilibrium point, making it very useful to spread your religion to City-States even without the Papal Primacy belief.


Note that highly situational Pantheons aren't covered here. Faith Pantheons in particular are useful for reaching a religion sooner.

Fertility Rites

Get more out of those maritime City-States with a 10% food bonus. This stacks multiplicatively with your UA, giving your capital 4.95 food per allied City-State rather than 4.5, for example.

Goddess of the Hunt or Sun God

I tend not to list the more situational belief options for Civs, though it's worth pointing out the effectiveness of a food boost. Together with maritime City-States, your citizens can generate all the food you need with a small number of tiles, freeing up plenty for specialists or working other kinds of tiles.

God-King

Get a friendship with a religious City-State early enough and this Pantheon is particulary potent. The science, culture and production is particularly effective early on.


Papal Primacy

With Consulates from the Patronage tree as well, every City-State following your religion will have a resting point above the friendship level; permanent friendship in other words. This allows you to get a lot out of your UA without having to spend any money. Notably, as well, there's no need to spread your religion to other full Civs unlike Tithe or Church Property, avoiding possible diplomatic trouble or cultural Civs having a bonus to tourism with you.

Tithe

Can't manage Papal Primacy? Tithe is a perfectly decent option to get extra cash for City-State friendships, and it works well with building tall.

Interfaith Dialogue

If you want to squeeze all the science you can, and your religion is not likely to dominate, here's a possible alternative option. Tithe and Papal Primacy will probably be more effective, but it's a backup for a backup if needed.


Swords into Plowshares

With Fertility Rites, you'll have a 25% growth bonus while not at war (on top of the growth bonuses from the Tradition tree) making those maritime City-States even better.

Religious Community

Tall cities can really make use of this belief to boost production, helping you to build wonders and spaceship parts in particular.

Divine Inspiration

If you can use the high production of your tall cities to grab a few wonders, this belief rewards you with plenty of faith to help spread your religion to City-States.

Feed the World

A complementary source of food to go with maritime City-States. As mentioned before, getting lots of food by unconventional sources allows you to free up some citizens to work other tiles or fill specialist slots, which makes you more able to switch into a full-production mode for building wonders, for example.


Religious Unity

A strong edge to religious pressure in City-States is good for maintaining the slow influence decay (and raised influence resting point of Papal Primacy.) For distant City-States, far away from your other cities, you can use International Trade Routes to more effectively spread your religion.

Missionary Zeal

Siam's faith before the industrial era will mostly go towards maintaining City-State alliances through Missionaries or Prophets. Making Missionaries more effective helps swing City-States to your faith faster, as well as re-establishing your religion in your own cities if someone's thrown a Great Prophet into your lands.

Holy Order

Cheaper Missionaries are handy for initially spreading your religion to City-States and your own cities that lack it already, though Missionary Zeal will be more useful later on, where rapidly overturning a rival religion in a city will be easier with stronger Missionaries than more frequent ones.

A great side-effect of all those City-State alliances for food, faith and culture is that they'll start helping you out at the World Congress. Many diplomatic Civs won't necessarily seek lots of City-State alliances until World Leader votes are about to start, giving you a window of time to skew the World Congress the way you want. Pushing through a World Religion and/or a World Ideology will work well to back up your delegates.

Note "priority" refers to how high you should prioritise your votes if it comes up, not how much you should prioritise putting them forward. Note also that voting choices can vary depending on your game.

Arts Funding

High priority
Vote no

Cultural Heritage Sites

Medium priority
Vote yes unless you lack wonders or a cultural Civ has plenty

While cultural Civs will get more tourism out of this policy, you'll get more culture to defend against them.

Embargo City-States

High priority
Vote no

A City-State embargo would not only crush your chances of using the Treaty Organisation tenet (useful for any route as Siam,) but it'd also force you to trade with full Civs for gold, who can leech science off you.

Historical Landmarks

Medium priority
Vote no

International Games

Medium priority
Vote no

International Space Station

High priority
Vote yes unless a scientific victory seems unrealistic

Lots of end-game science potential here, and a little production too. Even when you've begun building the spaceship, science tends to be a bigger barrier to completion than production.

Natural Heritage Sites

Low priority
Vote no unless you have a Natural Wonder of your own

Nuclear Non-Proliferation

High priority
Vote yes

Ban them early and keep them banned forever.

Scholars in Residence

Medium-High priority
Vote no

Sciences Funding

High priority
Vote yes

Whether going for science or diplomacy, this is worth voting for.

Standing Army Tax

Low priority
Abstain

The extra gold cost is somewhat annoying when you're trying to please City-States, but then again, this is a great way to hold warmongers back. No need to anger anyone over this.

World's Fair

High priority
Vote yes

This is a lovely opportunity to deny victory to cultural Civs. Doubling an already high culture output also works well to rapidly chew through those remaining Social Policies and tenets.

Tall cities are good at building wonders. Here's a selection of some of the best wonders, arranged in alphabetical order per era. Obviously, you won't be able to get them all, and some not listed here may be situationally helpful.


Great Library

Highly-competitive and near-impossible to get on the highest difficulties, the Great Library will get your science off to a great start if you can manage it.

Stonehenge

Need an extra hand up setting up an early religion? Stonehenge can help there.

Temple of Artemis

A food bonus to complement maritime City-States is on offer here. This affects base food (before it's eaten by citizens) so, if you have 10 food in a city and 5 being eaten, the net food will be 6 rather than the 5.5 you'd get from a 10% growth bonus.

On top of that, you'll have a bonus to ranged unit prodction to help defend before and after the time of Naresuan's Elephants.


Colossus

An extra Trade Route will really help out with getting gold for City-State alliances.

Hanging Gardens (Tradition Only)

You can build this in your capital for a truly enormous city by the end of the game, or maybe in a different city to even things out (after all, excessively large cities end up filling all their specialist slots and eventually end up working fairly unproductive tiles.) Either way, it's a great wonder, but remember it's fairly fiercely competed over.

Oracle

A free Social Policy at this point of the game is great for Siam as you can rush through the important Patronage tree quicker, giving you more time to make the most out of those bonuses. After all, the sooner you get Scholasticism, the more science you can get.

Petra

Like the Colossus, good for the extra trade route. Of course, making a super-productive desert city is nice, too.


Borobudur

Helps get your religion spread faster. An early edge to religion-spreading gives you advantage that can last the rest of the game, as religious rivals must deal with a large number of cities all placing pressure on each other.

Chichen Itza

Tall empires are more likely to reach Golden Ages, and the extra cash, production and culture from extended Golden Ages will all really come in handy. This is a fairly competitive wonder, so if you don't think you're first or maybe second to the technology, it may be best to go for something else instead.

Hagia Sophia

Either enhance your religion if you haven't already, or convert up to four City-States to your will. That could mean four permanent friendships established earlier on, with the Papal Primacy founder belief and Consulates Social Policy.

Machu Picchu

More gold and faith for winning over City-States with.


Forbidden Palace (Patronage Only)

A high-priority wonder. Reduced unhappiness is handy even for tall empires, but the extra two delegates is the real strong point here, particularly early on in the World Congress where it, along with a few City-State allies, can let you push through pretty much anything you want. Because your uniques are on the two technologies that feed into Banking, required for the Forbidden Palace, there's very little reason not to grab this wonder.

Leaning Tower of Pisa

Competitive, but a free Great Person and faster Great Person generation is good for pretty much anyone.

Porcelain Tower (Rationalism Only)

A free Great Scientist is nice, even if you can't get those powerful Research Agreements going. And if you can, well, enjoy getting more science out of them than the other Civ does.

Sistine Chapel

Laugh in the face of those cultural Civs! Ruin their plans for cultural domination! Eat up Social Policies for breakfast, even in the evening! Why? Because you're in charge of your own culture, and if you want to eat breakfast in the evening, you can do that! Want to ride a zebra into a cinema? You can do that! Want to make Civ 5 the national sport? You can do that too! Because you have Wats! And you have extra cultural City-State culture! And you have the ceiling of a famous building to back that up! What does Brazil, Egypt or France have to stop you? Nothing, that's what!* For you are the King of Siam, and no amount of tourism can take that away from you!

*Disclaimer: See the Counter-Strategies section.

Taj Mahal

Returning to sanity once more, the Taj Mahal can also help out with a quick burst to culture, and gold and production's good too. A lower-priority wonder, but still handy.


Cristo Redentor

Chewing through the last few tenets is faster thanks to this wonder. It's particularly handy if you want to take both Treaty Organisation and Space Procurements so you can save money from the first level three tenet to help fund the second.

Statue of Liberty (Freedom Only)

Lots of production! And a Social Policy! That'll really help out for building the spaceship faster, in particular.


Great Firewall

Probably no Civ can exploit the Great Firewall to its fullest extent as much as Siam. You can make it much harder for rival Civs' spies to steal science off you, and it also renders The Internet technology useless against you, making life even harder for cultural Civs.

Sydney Opera House

And just because you wanted another nail in the cultural Civs' respective coffins.


Hubble Space Telescope (Scientific Siam favoured)

Makes the Spaceship faster to build, and those free Great Scientists reduce the problem of science, too. Generally a must-have wonder for scientific Civs.

Siam is a bit more complicated and less straightforward than your average Civ, and as a result it's easy to make slip-ups. Here's a selection of some, which may or may not be already mentioned earlier in the guide.


Siam has no unique bonuses to retaining City-State allies. Diplomacy is a backup if you can't manage science, using the bonuses from religion and the Patronage tree to help out, but any other diplomatic Civ is better at getting City-State alliances than you.


Okay, cultural victory may be viable in your game if you grab the right wonders early on, or it ends up becoming the only viable victory path, but otherwise Siam lacks any bonuses to tourism, the main component of cultural victory. City-State culture and Wat culture isn't added to tourism with Hotels, Airports or the National Visitor Centre.


Unless you're threatened with war, it's better to research Education before Chivalry. That's not necessarily because of the culture bonus, but because it's useful to have Universities up and running as soon as possible for a scientific Civ.


They're good against most things on land in the medieval era, including most unique units (Impi, Keshiks and Camel Archers are notable exceptions) and many renaissance land units, too, but against Galleasses and Frigates, Naresuan's Elephants are powerless. Be sure to have a few ranged units to back your elephants up.

Siam gets lots of culture, has a good incentive to hold on to City-State allies and has an effective midgame defence, but has a particularly high vulnerability to diplomatic Civs.

Note that I'm only discussing uniques here, not the AI playstyle.


Siam has a strong incentive to befriend or ally cultural, religious or maritime City-States, but lacks advantages to doing so, making it fairly easy to overturn an alliance of theirs if need be.

Denying them religious City-State alliances early on can ruin their chances of a good early religion, thus making it harder for them to hold friendships and alliances. Of course, taking the Papal Primacy founder belief and thus denying them it helps, too, but for many Civs, that would be diverging too far from the standard course of action.

After they've got a religion (or have been denied one,) maritime City-States will be the backbone of their scientific route - their main aid to building tall. Deny them alliances and only their capital will gain from the City-State food, which makes it harder for them to construct spaceship parts or wonders in cities besides their capital.

In the later stages of the game, seeking alliances with mercantile or even militaristic City-States is a reasonable way to help match their number of delegates in the World Congress without the instability of competing with them over City-States.


Like UBs in general, there's not a lot you can do to stop Wats. For non-cultural players, all you need to know is that they'll be a bit faster at chewing up land and Social Policies. For cultural players, try to get plenty of tourism boosts going on Siam. Setting up an International Trade Route with Siam and putting a Diplomat in their capital are good ways, as it's hard for Siam to stop them.


In the medieval era, the main advantage of Naresuan's Elephants is their sheer strength. In the renaissance era, the main advantage is their cheap price.

At first, Pikemen will still be fairly effective against Naresuan's Elephants, as they are against regular Knights. Their effective strength against those elephants will be 24, one point below, but Pikemen have a 25% lower production cost than Naresuan's Elephants, so in the long-run you can get the upper hand. Be wary about bringing Knights in their land. 20 strength vs. 37.5 is not really a fight you want to have.

Musketmen are as good as Pikemen against Naresuan's Elephants, but they're a little more expensive. Be wary of picking up Metallurgy too early if in a prolonged war with Siam. Lancers are much more expensive than Naresuan's Elephants and have a disadvantage in a one-on-one fight. Plus, there's the risk of losing horse supplies and getting a 50% combat penalty, or not having enough horses to build new Lancers in the first place.

Once you've got industrial-era technologies, the main threat of Naresuan's Elephants are as a cheap Cavalry-counter, but that's rather negligible in the grand scheme of things.


Most diplomatic Civs are effective against Siam due to their ability to rapidly turn City-States to their side (which Siam can't easily respond to,) but Arabia is particularly potent against Siam due to their Camel Archer UU.

The main vulnerability of Camel Archers typically is being attacked by Knights, due to their higher strength, but mostly their speed (bonuses vs. mounted units don't work against mounted ranged units, so Pikemen aren't an effective counter to Camel Archers.) The slower speed of Naresuan's Elephants also makes it difficult for Siam to deal with Camel Archers.

So, why Arabia and not Mongolia? After all, Mongolia gets a bonus to City-State conquest and a UU that's like the Camel Archer, but faster. Well, the answer's in religion. Arabia's start bias puts them in a good position to grab the Desert Folklore Pantheon and build a strong religion early, letting them snatch Papal Primacy before Siam can pick it up. Arabia also has a bonus to religious spread via Trade Routes, which can make them convert distant City-States more easily than Siam. That severely weakens Siam's religious arm of their strategy.


Early-game Aggressors - Siam lacks defensive bonuses early on (and their start bias makes them a bit more likely to spawn in open land, which is easier to invade.) They may have an above-average size early army in order to clear encampments for City-State quests, but they shouldn't be any great feat to defeat.

Mid-game Warmongers - It may be best to avoid invading Siam for now unless you've got a mid-game UU that can deal with Naresuan's Elephants. Come back later when their defensive advantages are weaker.

Late-game Warmongers - Watch out for Siam's City-State allies. Typically, you'll want the war to be over quickly before those forces can cause you any trouble. Target their capital and bring plenty of Artillery, Bombers or other such units to batter down their defences. Without their maritime City-State-assisted super-tall capital, Siam will be left rather weak.

Cultural Players - Siam is likely to be one of your key barriers to cultural victory due to the sheer amount of culture they can generate. Maintain an International Trade Route with them and place a Diplomat in their capital. Send Great Musicians their way to make use of concert tours. If they're friends with you, you should be able to secure an Open Borders agreement and if you lack a religion of your own, letting them spread theirs to your cities can give you a tourism bonus from having a shared religion. If you don't get on well with them, you can always try competing for cultural City-States to lessen their cultural growth.

Diplomatic Players - Use your advantages to buying or holding City-State influence to deny Siam maritime City-States in particular (as they help their scientific aims more than the other two types they have bonuses for) if you can spare the cash, or go for mercantile and militaristic City-States (which will be less competitive) if you can't, to lessen Siam's influence on the World Congress. If Siam's forced out of a scientific victory, you should have an advantage to beating them to a diplomatic one.

Scientific Players - Competing for maritime City-States can help lessen Siam's ability to build tall and get lots of science that way. Tall-building scientific Civs can use excess Spies to help there, while wide-building ones can use trading post gold or higher levels of faith to assist with that.

If you like these guides and want to send a tip, you can click here![ko-fi.com]


These guides cover every Civ in the game and can be used as quick reference guides.

• Civ summaries (Gives a brief overview of how each Civ plays)
  
• Civ-specific tricks, secrets and clarifications (Compiles the lesser-known features of each Civ)

All 43 Civs are covered in in-depth guides linked below. In brackets are the favoured victory routes of each Civ.

• America (Domination)
  
• Arabia (Diplomatic/Domination)
  
• Assyria (Cultural, Domination and Scientific)
  
• Austria (Cultural, Domination and Scientific)
  
• Aztecs (Domination/Scientific)
  
• Babylon (Scientific)
  
• Brazil (Cultural)
  
• Byzantium (Cultural/Domination)
  
• Carthage (Diplomatic/Domination)
  
• Celts (Cultural)
  
• China (Domination)
  
• Denmark (Domination)
  
• Egypt (Cultural)
  
• England (Domination)
  
• Ethiopia (Cultural/Scientific)
  
• France (Cultural)
  
• Germany (Diplomatic/Domination)
  
• Greece (Diplomatic/Domination)
  
• Huns (Domination)
  
• Inca (Scientific)
  
• India (Cultural/Scientific)
  
• Indonesia (Diplomatic/Domination)
  
• Iroquois (Domination/Scientific)
  
• Japan (Domination)
  
• Korea (Scientific)
  
• Mayans (Scientific)
  
• Mongolia (Domination)
  
• Morocco (Diplomatic)
  
• Netherlands (Diplomatic, Domination and Scientific)
  
• Ottomans (Domination)
  
• Persia (Diplomatic/Domination)
  
• Poland (Domination)
  
• Polynesia (Cultural)
  
• Portugal (Diplomatic)
  
• Rome (Domination)
  
• Russia (Domination)
  
• Shoshone (Domination/Scientific)
  
• Siam (Diplomatic/Scientific)
  
• Songhai (Domination)
  
• Spain (Cultural/Domination)
  
• Sweden (Diplomatic/Domination)
  
• Venice (Diplomatic)
  
• Zulus (Domination)