Brave New World is the second giant expansion pack to be released for Sid Meier’s Civilization V, which was originally released in November of 2010. The previous release — last June's Gods and Kings — was a wonderful addition to an already challenging and addictive game.

But regular play of Civilization V and its first expansion made something clear to many players: the last third of the game could be a little monotonous and slow-feeling, especially if you were shooting for a Cultural Victory. Enter Brave New World, which will be available for PCs tomorrow. Dennis Shirk, senior producer for the Civ series, told Polygon in February that community feedback had alerted him to the game's weaknesses, and that Gods and Kings would take aim at those problems. But 2K Games, which produces Civilization, also made clear at the time that the expansion would be massive, and would add new features to nearly every aspect of the game rather than simply fix the current version's inadequacies.

Brave New World adds nine new civilizations and leaders, including Casimir III of Poland, Maria I of Portugal, and Shaka of the Zulu. This brings the total number of playable civilizations to 36, including the previous nine civs added by Gods and Kings. Additionally, there are two new scenarios (the "American Civil War" and "Scramble for Africa"), and eight new Wonders, which include Broadway, the Globe Theater, the International Space Station, and the Uffizi. These additions are welcome, fun, and like the Gods and Kings expansion, add a new layer of complexity — at least statistically — to the game. The more options the better, right?

But, like the previous expansion, Brave New World doesn't simply add new options to existing gameplay structures. Whereas Gods and Kings added game-changing Religion and Espionage features, Brave New World tinkers significantly with the tone and feel of the game by changing the way Culture — and Cultural Victories — work. In practice, rather than simply amassing Wonders and Great People as before, a player can now complicate the Culture process by giving those Great People the ability to create specific "Great Works." There are now Great Artists, Writers, and Musicians, rather than just generic Artists. Thus, Proust might be born in your city, and you can now direct him to produce a Great Work like In Search of Lost Time. Once created, that work needs to be placed into a "slot" within a Cultural Wonder or Museum, and the works are amassed in this way to produce Culture.

The new measure of Culture is Tourism, which is your ability to attract other cultures to your culture — one of the steps to winning a Cultural Victory. Brave New World also adds the ability to build a new cultural "unit" — The Archaeologist — once Archaeology has been researched. This unit can then be sent out onto the map to excavate sites, resulting in cultural Landmarks or additional Great Works. Further changes have been made to the cultural map by tweaking the Policies screen to include "Ideologies" (Freedom, Order, and Autocracy) which impact your victory conditions.

But the updates and changes aren’t simply cultural additions. International Trade Routes are a new, more complicated way of dealing with trade, while the addition of the World Congress adds a new layer to Diplomacy, which often seems to be the weakest facet of Civilization V.

So, what does all this add up to in gameplay? Well, old players will find themselves in familiar territory, and only the tweaks to the way Great Artists and Works are handled will give any pause. In practice, this expansion is massive but subtle, and not as jarring as the last expansion’s addition of Religion seemed at first. And, if players did have any gripes about the game lagging in the second half, Brave New World does indeed combat some of those issues, making the latter part of the game less monotonous and more engrossing. Having played through two full games with the expansion, it’s clear to me that the additional features renew a game that might be aging a bit for previously addicted players like myself. The new features, civilizations, and Wonders are enough to suck you back into the game and get you playing for hours on end like you might have months ago.

Like Gods and Kings before it, the full breadth of this expansion can't be taken in through just a few cycles of gameplay, and only time will tell just how addictive this new iteration of Civilization V will be. But if the past is anything to go on, the answer is... very addictive. Be sure to check out Polygon's full review of Civilization V: Brave New World.

Civilization V: Brave New World is available tomorrow for PC.