If you're working your way up to deity difficulty, these are the essentials to remember. However, like most things in life, these are general rules, which are meant to be broken in the right situations.

• Play according to your civ/leader's strengths
  
• Build with your adjacencies:
  • Science and production buildings like resources
    
  • Culture and happiness buildings like mountains
    
  • Food and gold buildings like water (the coast or navigable rivers)
• Remember to manage your resources whenever possible, reallocating where necessary. Trade for as much as you can.
  
• Settlement limits! The most recent updates have hard nerf'd the city maxxing meta. You need to now be very selective with your cities.
  
  • Limit your cities to 2 per age, i.e. 2 in antiquity, 4 in exploration, 6 in modern; going under this limit is fine, going above this limit is dangerous for your gold income/food
    
  • Unless you're at war and are looking to capture more settlements, you can generally stay at one or two settlements above your settlement limit
    
  • If you have a lot of happiness (i.e. every settlement has more than 35 happiness being generated), the settlement limit is a myth. Resort towns are great later on to hit this threshold
• Regroup vs continuity is up to you, while continuity is the default now, it also simplifies a lot of the age transitions and allows for some cheese. Having played with both, I'd recommend continuity if you're making your way up to deity difficulty
  
• Momentos, while nice to have, aren't game changing, I stick to a basic attribute points, 1 each in science and culture
  
• Having a strong military dissuades the AI from attacking you, so even if you want to play a sim city style of game, you want to keep a decent military around
  
• Scouting even past the antiquity age helps you avoid surprises

• Commanders are super important, and getting that first commendation on them is vital. I find the assault tree to be the most important to fill out first, but any of the trees is fine as long as you get at least one commendation on them. Aim for the following at a minimum (2 more to each number here if you're playing with regroup mode):
  
  • Antiquity: 2 army commanders
    
  • Exploration: 3~4 army and 2 navy commanders
    
  • Modern: 5~6 army, 3~4 navy, 2 aerodrome and 2 squadron commanders
    
• Always celebrate.
  
  • Choosing the extra celebration length is a bit of a double edge sword depending on the leader:
    José Rizal for example benefits greatly from this, but the Ashokas generate enough happiness where they'd rather pay the exponential cost of celebrations
    
  • A celebration means additional policy slots, if you're going for extra celebration length it reduces your overall number of policy slots over the time period of an age
    
  • Try to always generate enough happiness to chain celebrations; resort towns are your best friend here
    
• Monitor the age progress. Except in the modern era where age progression doesn't matter, you really should minimize your impact on the game speed as much as possible.
  
  • You can find the current age progression by highlighting the little percentage under the meter on the top left of the screen. On standard speed the age progress goes up to 200 by default. This is not the same as the turn counter. The age ends when the maximum age progression is reached, regardless of the turn counter
    
    
  • Minimizing age progression is important to give you enough time to complete all the paths and let your towns grow as much as possible before the age transition
    
  • Completing legacy paths before the age naturally ends or researching future tech/civics while you can research other things or removing a civ from the game all contribute the the age progress
    
• Specialize your towns. More. (Obviously, once you have collected all the resources in that town's region. Depending on the yields, you might want to collect some of the tiles too.)
  
  • Fishing/farming towns where you you have bad or no adjacencies
    
  • Mining towns if you have a lot of mines
    
  • Urban centres where you have good adjacencies for buildings (Consider making these a city later on)
    
  • Resort towns in settlements if you have a lot of mountains/natural wonders that you don't want to make a city out of.
    
• Look through the list of narrative events (here[civilization.fandom.com]) and look to trigger as many of them as possible
  
• Building every possible thing in your cities isn't worth it:
  
  • Avoid ageless buildings (excluding civ unique) in your cities unless they are absolutely necessary (the Ironworks in the modern age is a good boost to production and hence worth it for example)
    
  • The production cost on new buildings increases with each building in the settlement, avoid making costs balloon in the later parts of the age as well later ages
    
• Holding production to rush certain builds (like wonders) is something to keep in mind, especially in cities with lower production
  
• While at war, if you see an AI building a wonder you want, you can send a combat unit to sit on that tile to prevent the build from going through.

By far, the most difficult part of the play through to get a perfect score in.
Yield priority: Production > Science > Culture > Gold > Influence > Happiness > Food

The most important things to do in within the first 50 turns in no particular order:

• Placing your capital: While you don't have much choice, I recommend having at least 3~4 coast /navigable river tiles in the capital and your second city to give yourself enough space later on
  
• Scout, scout, scout? I go for a double or even triple scout opener to get as many goodie huts as possible
  
• Tech rush: While library first isnt as strong as it once was, this one heavily depends on your starting position. Typically, if you have:
  
  • Lots of rough terrain for mines, go library rush
    
  • Lots of forests and woodcutters, go monument rush
    
  • Lots of water? restart nah, the new update has made this very viable too, rush sailing into either library or monument
    
• Civics: If you see more than a couple of hostile independent powers around you, consider rushing Discipline over Mysticism. Always complete your civ's unique civic tree, as those carry on through the ages
  
• Even if you're playing Carthage, the first settler you make should be sent to place your second city
  
• Space to build can be at a premium, so watch out about putting down too many ageless buildings
  
• Give your cities room to breathe, your capital and any other settlement (if you want to make it a city later on) should ideally take up the maximum space possible
  
• Prioritize befriending non hostile independent powers, especially if you're going to settle near them (if you settle too close to non hostile independent powers before you "become friendly" with them they will become hostile). You do not need to befriend every independent power, leaving some for the AI benefits you in the long term.
  
• Evaluate your civ's unique buildings, while the bonus of building a unique quarter is generally pretty good, some of the unique buildings are not worth building. If you cannot afford the production, its better to skip these
  
• Hold on to completing some of the legacy paths until the last turn of the age, but only if you know you can complete these in one turn. This minimizes the age progression, giving you enough time to complete the other tasks at hand
  
• In this part of the game, keeping up with the AI's massive buffs is the most important thing. Keeping up with the AI here allows you to outpace the AI later on

Typically, I find the difficulty of the path to be: Culture > Militaristic > Science > Economic. I tend to focus on the culture and militaristic points along with setting up the foundations of the empire up until about 60% of the age progression. Thus, while not impossible with any leader/civ, for your first deity game or if you want to achieve this victory condition, I recommend a cultural/militaristic leader/civ combo to make it easier. I tend to go through the age, finishing the paths in that order.

Goal: Build 7 wonders
The main focus of the first 60% of your antiquity age should be to prioritize getting as many wonders as possible. Remember to keep your culture high enough to keep unlocking the wonders at least at the same pace as the AI, as you should be outpacing

• Both the Great Steele and the Gate of All Nations are S tier wonders to rush, regardless of what civ you're playing
  
• Prioritize your civ specific wonder depending on how late it is in the tech/civic trees: For example, Angkor Wat is places relatively early in the Khmer unique civic tree as compared to the regular tree, so can be your 6th or 7th wonder if you're playing Khmer without the AI sniping it from you
  
• Split your wonders across your cities: If you're following this guide I recommend 2 cities for this age, and split the wonders across both: I try for at least 2 wonders in the second city, if not more.
  
• The Colossus and Great Lighthouse are both S tier wonders in my opinion because they can be placed on the coast, saving you space on land
  
• The Mausoleum at Halicarnassus is S tier for its effect of riving Cavalry, but difficult to get because the AI seems to rush it
  
• Most other wonders are decent, and you should build as many of them as possible even if only to deny the AI

Goal: Gain 12 points
Your settlements give you +1 point and captured settlements give you +2 points. Given your settlement limit in most games is going to be between 6~8, it is a guideline of how aggressive you need to be.

• Befriending militaristic or expansionists independent powers has a chance to give you +1 settlement limit, helps in cases where you aren't going to be aggressive.
  
• Ideally, you should aim to capture a minimum of
  
  • 4 settlements if your civ has no increase to settlement limit in the unique civics
    
  • 2 settlements if your civ does.
    
• Capturing enemy controlled independent powers is usually easier, and still counts as +2 points for this path
  
• Consider incorporating independent powers (this takes 10 turns so plan accordingly) if they are positioned well
  
• Once you have 10 points and are at your settlement limit, move 2 more settlers to new spot and wait for the last turn of the age to settle them.
  If you follow this, you should have this path completed and be setup for the next age. You should really avoid getting more settlements than your settlement limit + 2.

Goal: Get 12 codices
If you're keeping up with the AI in terms of science, this path should be relatively easy. You get codices by researching masteries. This path should be your main focus in the last 20% of the age. You also need to display these masteries so make sure you have enough space.

• Always take the codex when possible. You would rather have too many than too few
  
• Once you have the basic techs unlocked and are in the mid/late game, go for mathematics and its mastery to start getting the codices. Delay Iron Working until you have all the codices
  
• There is a sneaky codex in the civics tree at Literacy which you should get after maxing out your settlement limit
  
• If your science generation is good enough (which it should be if you're following this guide), most masteries will be 1~4 turns worth of science away.
  
• Libraries give you 2 places to house the codices and Academies give you 3, so 2 libraries and 2 academies (i.e. one of each in each of your cities) is enough space to house all the codices
  
• If you're struggling with science generation or space to house the codices, convert towns to Urban centres and place libraries in them until you hit your goal.
  
• If its the last 5% turns of the era and you still don't have the codices, run Research Initiative in your cities to boost science output
  
• If you have all the codices and there still is age progression, hold off on slotting them in until the last turn

Goal: Slot in 20 (city/bonus) resources
This should be an easy auto complete if you're trading enough.

• There are three kinds of resources, and only two of them counts:
  
  • City resources: can only be slotted in cities; Counts for silk roads
    
  • Bonus resources: can be slotted in cities and towns; Counts for silk roads
    
  • Empire resources: Empire wide bonuses, Does NOT count for silk roads
    
• If you've not hit the resources required with the last 5% of the age remaining, buy merchants in settlements close to other AI settlements and send them out to get city/bonus resources

Goal

Significantly easier than the antiquity age, this is the point of the game where you should begin to outpace the AI.
Yield priority: Production > Science > Gold > Culture > Influence > Happiness > Food

• Fealty is the first take for the +2 settlement limit
  
• I prefer going for a scientific golden age to give myself a science boost in the beginning of the era and that none of the economic golden ages are worth as much
  
• After these two, spread out the other legacy points as you see fit (Keep in mind, certain breakpoints with attributes generate more value than others, at 3, 5 or 7 attribute points in most trees)
  
• Moving your capital is up to you, doesn't really effect too much

• In the technology tree, go Astronomy to Cartography to Ship Building
  
• In the civics tree rush Piety
  
• Buy 4~6 scouts at different parts of the coasts and send them out to discover the Distant lands as soon as you complete Cartography
  
• Convert your old city (cities?) and pick a new settlement for your 3rd city - Aim for 2~3 cities in homeland and 1~2 cities in Distant Lands.
  
• Rush building a temple, so you can get a pick on your religion's abilities. Consider getting Theology (from the unique religion civic tree) during the early middle part of the age
  
• Go through and befriend independent people, as many as you can, prioritizing the non hostile ones. Especially good if you can befriend Distant Lands independent people, they do the scouting for you.

Do not make more than 5 cities at the end of the age - the hit to production costs, and gold/food income is not worth it. If you believe you need more science or culture, buy those buildings in your Urban Centres. Legacy paths in this age are easier to complete and while they take a little bit of planning, should generally be achievable without much hassle.

Goal: Gain 30 treasure fleet points
This path requires the most amount of planning: Settle in the Distant Lands, improve the treasure resources and move those treasure resources back to your homeland settlements to cash them in.

• you need to have 6 or more treasure resources improved in Distant Lands at about 50% age progress to guarantee completing this path
  
• The Havana Harbour is an S tier wonder that can only be built in Distant Land Cities that gives +3 points to treasure fleets leaving that settlement, giving you more flexibility with your settlements
  
• Consider settling island chains even if they have no resources to make the passage between the Distant Land and Homeland cities safer
  
• After moving the treasure convoys back to the homelands, I avoid cashing them in until the last turn of the age to minimize age progression
  
• Privateering treasure convoys from other civilisations is an option, but unreliable. It hurts your reputation with other civilisations but it slows them down too.

Goal: Gain 12 points
Your settlements in Distant Lands count for 1 point, captured settlements in Distant Lands count for 2, and converting them to your religion (considered at the time the age ends) doubles each of these. This path is why you need good culture this age, as you can get a +5 on your settlement limit just from the default civics tree.

• If you plan to play entirely peaceful, you need 6 Distant Land settlements of your own converted to your religion (at the age) to complete this path
  
• Through the war path you need only 3 Distant Land settlements converted to your own religion to complete this path,
  
  • Look to get Distant Land settlements either through your own conquest or through peace deals from the AI
    
• I recommend at least 3 settlements and one city in the Distant Lands, and capturing a couple to stay within your settlement limit (or that +2, with good happiness)

Goal: To acquire and display 12 relics
This path is trivial, frankly, confusingly so: you should be able to complete this in all your games. The key to me was to realize that (a) in most cases the Founder Beliefs (which are the buffs you get by converting with religion) are super weak in my opinion - not worth focusing on, (b) Missionaries are not permanent and have limited charges, and (c) the AI is relentless with spreading its religion

• Get your first temple down asap, and look for beliefs you can reasonably achieve
  
  • Reliquary beliefs: Bhraminism (+2 relics for converting capitals), Evangelicism (+1 relic for converting distant land settlements) are the most reliable, but most others will be just fine
    
  • Founder beliefs: While mostly non consequential, some of these can be decent. I go for Salat (All buildings get +1 happiness with temples) to be able to use them as band-aid fixes to happiness
    
  • Enhancer beliefs: Unlocked with theology, Crusade (+1 free War Support), Parampara (+1 Great Work slot in Science Buildings in cities), Sanctum (+1 Great Work slot in Temples in cities) are all great to have
    
• Once you put down your first temple and select your beliefs, ignore this path till about 60% age progress.
  
• At around the 60% mark, reallocate all the incense you have to one city, and use that city to pump out missionaries before the crisis starts. Move them to the target locations as per your Reliquary beliefs
  
• Wait to convert the population until the last 3 turns of the age, and convert all the places at once to minimize impact on age progress
  
• Remember to send at least 2 missionaries to each of your distant land settlements to guarantee Non Sufficit Orbis, and convert your own settlements only in the final turn of the age

Another trivial one, but this time a default win if you are building your cities according to adjacencies. I can't remember the last time I didn't complete this path on accident sometime during the playthrough.

This era has the most amount cheese with the final turn completions, but I fail to see what the developers expected otherwise.

• Make sure to buy all the ageless buildings in all your towns that have no scope for being a city
  
• Buy at least the Dungeons in your Urban Centres, if not everything, the +4 influence base on them is great to have and adds up very quickly
  
• At this point in the game you should be handily outpacing the AI in all aspects and ready to take on the modern era

Goal:

General things to watch out for, starting from the least impactful to the most in my opinion

• Plague: Apart from an opportunity to get a free migrant, this one crisis isn't really doing much. You move your units out of your city/town centres and you can more or less ignore it. Repair the buildings as they break, and unless you have a settlement where you absolutely need to buy something while it is in unrest, the plague doctor isn't worth it either
  
• Revolt (Antiquity): A settlement limit check in disguise, as long as you babysit your happiness, pretty easy to deal with. On the bright side, it allows you to buy villas in towns, helping you boost influence. A fun thing to do is to sanction the AI for happiness, usually enough to push some of the towns enough to have them shift to your side as long as you are the closest other civ to it.
  
• Revolt (Exploration): Go for the Religious Tolerance (+8 Happiness in Settlements that do not follow your religion. -2 charges on new Missionaries) option, if you're following this guide that should be all your settlements anyways. Remember to convert settlements for the Toshakhana part in the final turn though.
  
• Revolution: Exploration exclusive, super nice to have, choose the +40% gold, repair buildings, profit. Gets very silly with the gold generation, again, managing happiness is key.
  
• Invasion: An antiquity exclusive, encampments spawn with really strong troops and if they spawn near you are a ticking time bomb. Best to clear them as soon as possible. If they are however far away from you, do consider throwing some influence into them to keep the AI occupied

The easiest age overall, I don't have too much to say about this part. If you've done everything up to this point well, this part shouldn't even be a race against the AI given how quickly you can complete it.

• Cultural: rush Natural history and its mastery, buy 5~6 explorers and keep them busy
  
• Scientific: Can be left for later on, as long as you maximize production initially, and buy the aerodrome and launchpad with gold
  
• Militaristic: Find the strongest AI, take the same ideology as it, and capture settlements till you hit the target
  
• Economic: The first thing to rush with science, get 5~6 factories up and running, fill in the resources and should be pretty straight forward to get

This is a set of tier lists based on my experience on how easy/difficult getting perfect victories are with the civs/leaders. This does not mean any combination is completely unviable, just that using their bonuses effectively is more of a challenge, and requires better gameplay. For your first few playthroughs I strongly recommend going with the S or A tier options when possible.

Given completing the cultural legacy is the most difficult part of completing that age, I prefer civs that give production/culture early.

With the new buffs, Egypt is absolutely broken with the sheer amount of production possible, and their unique great people make getting wonders a breeze.

In Exploration you can be a lot more flexible with your civ. You're looking to accelerate your growth past the AI, and most civs allow you to do that. I do not value having a strong religious presence for most of the game, so any civ with a unique missionary gets bumped down a tier automatically.

As you can see, the focus is on putting yourself in a good position to absolutely dominate in the modern age.

The touchdown for the playthrough, I value civs that can blitz out at least one of the paths.

The Unique Explorer from Britain is incredible, when combined with the Society of Antiquaries policy. The extra movement helps in getting to the spots and starting the excavation so much.

Some leaders make your life a lot easier. Note, it is Himiko Queen of Wa is S tier and High Shaman in B, their icons look too similar.