Sid Meier's Civilization VI launches October 21st. Post reporters Andrea Peterson and Brian Fung play the game for an exclusive look. (The Washington Post)

Civilization is celebrating its 25th birthday with a beautifully reworked version of the classic that puts players in the shoes of leaders bent on world domination. In Civilization VI (or Civ VI, for short), players can dig more deeply into their cities, thanks to a new twist that lets users tap their urban planning skills to fit specialist districts together in a beautiful urban jigsaw.

The result is a richly customizable, even more sprawling title than we’ve seen from the series in recent years. Players can win in one of four ways: by conquering other leaders’ capitals, leaping ahead in scientific progress, building up their cultural appeal to draw tourists or proselytizing the word of their own gods to the world.

Firaxis provided The Switch team with three review copies of a limited version of the game, which allowed for full playthroughs. The studio let us choose from a set of 10 of the game’s world leaders. Despite being a month away from its Oct. 21 release, the game was surprisingly polished — complete with narration superbly growled out by none other than Sean Bean.

There's almost too much to pack into one article, thanks to the preview's all-new slate of leaders — each with their own units and abilities. But here are some of our thoughts from the preview.

Urban planning

Perhaps the biggest change in Civ VI is the decision to unstack cities — a move that lets your metropolises sprawl across the map and develop unique districts for each urban center.

This makes things much more complicated, particularly in the early part of the game, but also can make building the cities themselves more rewarding. Certainly from an aesthetic point of view, we loved seeing the cities unfold, and to see monuments and wonders on their own squares — it made us relate more to the places we were building.

Some buildings are terrain specific — an aqueduct needs to have a source of water, for instance — which makes placement matter all the more. The same is true for the large construction projects, called Wonders in Civ parlance, which often need to be placed on specific terrain and can also affect the terrain around them.

The Pyramids rise -- specifically from a desert tile. (Courtesy of 2K Games)

Wonders now occupy their own tiles, rather than being shoved into the city at random, and you can see their construction progress over time. It’s a kick to see something like the Eiffel Tower or another landmark rise elegantly from the landscape and improve the appeal of the plots around it.

Barbarians at the gate

Civilization games always feature Barbarian tribes that attack your cities from camps that players must then wipe out. In Civ VI, the Barbarians are even less shy than normal, making it particularly difficult for young cities to take root.

The build of Civ we were given for this review was locked onto the standard "Prince” difficulty. But, if our playthroughs are any indication, there will be no need for a “raging hordes” mode that amps up the aggressiveness of these AI units.

It seemed that if Barbarian Scouts were able to return to their encampments after discovering a city, even more Barbarians than usual would spawn — adding another potential layer of difficulty.

Luckily, Civ VI also gives players more options to customize their own forces. You can apply new bonuses to entire categories of units, such as Scouts, giving them a more useful role in your armies. And combat units get fleshed-out promotion trees. So if you want to specialize one group of warriors to work better in direct melee combat, while another is more effective against ranged units, you can tweak (and name!) those units accordingly. That gives you a greater incentive to hang on to veteran units as well — luckily, unlike in Civ V, you don’t have to choose between healing and promoting a unit.

A faster technological revolution

Civ V’s tech tree was all interconnected — each new technology you researched led, directly or indirectly, to another technology. But that changes dramatically in Civ VI, with some technologies leading to dead ends. For instance, archery is one of the earliest technologies you can research, but you don’t need it to research any later technologies. That means it can be hard to justify investing time in archery or other orphan branches of the tech tree when you could be focusing on technologies that are prerequisites for more desirable advances down the line.

Since things are less connected, it’s also easier to speed through the technology tree, chasing after the techs that will help you achieve a science victory. (In this game, that means colonizing Mars! Elon Musk, call your office.)

It’s an interesting departure from the last Civ release, the planet-colonizing Beyond Earth, which ditched the tree model for a sprawling spider-web concept that was even more interconnected than Civ V’s approach.

Another technology tree change is the addition of bonuses. This feature gives you a boost toward researching technologies by completing other related actions. For example, building a quarry makes it easier to research masonry. Used strategically, these bonuses can help you rush through the tech tree and dominate your enemies.

Harald Hadrada, king of Norway. Likes ships. Hates weakness. (Courtesy of 2K Games)

Civic pride

Civ has also set up a civics tree in the latest version of the game, which lets you shape your nascent government independently from your technological progress.

Researching civics is a bit like researching technologies, except that your rewards come in the form of hot-swappable bonus cards that you can use to amplify your play style. Are you at war and need to build medieval mounted units more quickly? There’s a production bonus for that. Are you focusing on trade? Use the card that gives you extra income for every diplomatic envoy you send to a city-state.

Achieving civic milestones — discovering, say, “humanism” or “The Enlightenment” — unlocks new cards, which can then be mixed and matched depending on your style of government. As you progress, you get access to more types of governments, such as a Merchant Republic or a Democracy, which have slots allowing different types of cards.

While the civics mechanic adds a deep and interesting new layer to game play, we found it’s sometimes a little too easy to change policy cards. Every time you complete research on a new civic, you’re allowed to change out all your policies at no cost. This makes it possible to alter your government's footing on a dime, giving the player a tremendous advantage. It would be interesting if the game created scenarios where you can't change policies even if you wanted to, just as changing the laws in, say, a real democracy requires time and work.

As with researching technologies, there is a boost system where completing challenges gets you closer to unlocking a specific policy. For instance, meeting three city-states helps you get a lot closer to discovering political theory — which opens up a range of new government types.

Losing my religion

The new Civ also has a religious victory condition, which lets you win if you’ve spread your belief system through various types of missionaries to at least half of the populations in all your competing civilizations. In the couple of playthroughs we did while pursuing a religious victory (which we never accomplished), it became clear one had to really work to stay focused to keep a religion from being wiped out.

Even if you aren’t that interested in going for a religious victory, you may want to keep a few of the special defensive religious units on hand if you don’t want to be converted by another civilization.

Bonus thought: Civ VI also simulates religious conflicts between apostles as lightning fights, which look pretty awesome.

A shot of the game's version of the P-51 Mustang, a unique combat unit for America. (Courtesy of 2K Games)

Linking arms

Reviews being what they are, there was less time to play with the late-game atmosphere than with the early game. But, in later warfare, a new mechanic in Civ VI that lets you link combat units was very useful.

Long-time Civ players will know that the game used to let you stack infinite numbers of units together and pull them apart as needed. That changed in Civ V — and was not necessarily a popular change. With the new version, you can group identical units, but they will stay that way. No backsies.

But you can also make support units — a medic, for example, or a battering ram — and move them together with other units. That feels more flexible, in terms of customizing your units for battle, and less complicated to work with as well.

Is it as good as stacking units? Probably not, in terms of sheer force. But Civ's developers seem to have a penchant for unstacking.

In the end ...

The early game changes are particularly different and can make the overall course of your civilization feel a little less fluid, because there are so many things to keep track of. Then again, this also makes each decision count more, which is not necessarily a bad thing.

Overall, Civ VI’s additions are welcome and very attractive, but players familiar with the game will have to adjust to quite a few changes. Some may require players to change their usual play styles. It’s not so easy to turtle up and avoid combat, which probably means a more well-rounded playing experience. Then again, customizers needn’t worry. There are plenty of ways to leave your unique mark on the world with all of these additional options.