Civics are a new concept in Civilization VI. They encompass a civilization's philosophical and ideological progression, allowing for a player to concentrate on things like cultural development and diplomacy instead of just researching the latest military tech. Effectively, in Civilization VI your regular development over time is split in two: scientific and cultural, with both progressing simultaneously. But while scientific development focuses on technology, resources and military, Civics are the main way to develop your society and implement advanced diplomacy and new forms of government.
The Civics Tree
Civics are organized in a research tree, very similar to the scientific technologies tree from previous games. We can actually say that the traditional Tech tree has been split in two in Civilization VI, with the two parts being the two sides of the same coin: your civilization's development over time. Progressing through the technology tree requires Science development, while progressing through the Civics tree requires Culture development. And just like your technological research, you are constantly developing a Civic, right from the start of the game. There are 50 civics in the base game, with some not being needed to progress through to the end of the tree (a.k.a. "leaf techs").
The boost mechanics for the Tech tree are also present for the Civics tree - each individual Civic may be boosted by fulfilling an Inspiration requirement, similar to Eurekas in the technology tree. For a list of individual civics, see this page.
The main difference between the two trees (besides the way you progress through them) is in their concept, and the stuff they unlock. While the Technology tree offers military tech, and essential techs for dominating your surroundings, the Civics tree unlocks Social Policies (now called "Policy Cards"), diplomatic options, and subtle military developments, such as formation bonuses, or the ability to combine units into Corps and Armies. We can say that the Civics tree offers roughly half the progress opportunities in the game, related to culture and diplomacy, while the Technological tree offers the progress through military tech and raw science.
It is now fully possible for a civilization to develop along cultural lines, and still win the game without bothering with developing science. This allows for an entirely new focus in the game.
Era progress bar
Like the Tech tree, underneath the Civics tree in its scroll area you will find the Civic progress bar, which depicts the overall progress of the game (with the current turn marked on the bar), and where approximately each civilization stands in terms of civic development. You will see a number of circles on the bar, each one marking one or more civilizations. A circle marking a single civ bears its leader's portrait, and one marking multiple civs a number; scroll over each circle to see the exact Civic Era it shows, and (if it shows multiple civs) which leaders are currently in it. This way you can have a nice idea of where each civ stands in terms of development compared to the other civs.
- Main article: Policy Cards (Civ6)
The Policy Cards (a.k.a. "Policies") are the actual representations of the social orientation of your nation. Each Policy Card represents an effect, which is activated when you place the card in the appropriate slot in your Government. (For more info on how to do that, please see the Government article.) Policy Cards are unlocked via progress through the Civics Tree.
Old vs. New
Civilization VI's Civics system - and more specifically, the Government system - is actually Civilization V's Social Policy system revamped and expanded. Compared to the older game, the new Government system offers much greater flexibility and the possibility to adjust your Social bonuses on-the-fly as the game offers you new challenges. Whereas Civilization V: Brave New World's system presented a more steady and predictable development, it locked you onto a specific path with little possibility for maneuvering. While arguably more powerful, individual Social Policies there were usually too focused into a specific field to allow a civilization to respond to all possible threats (not to mention that once chosen you were stuck with them until the end of the game, for good or ill).
This is where Civilization VI's system really shines! While switching Governments is not that easy, switching individual Policies is very intuitive, and even if you do it only every several turns (when the free possibility presents itself with the development of a new Civic), you are still able to respond almost instantly to the ever-changing situation in the world. The four main types of Policies cover every aspect of the game, and offer an ever-expanding variety of ways to tweak your bonuses, from simple yield-boosting Policies to Policies which depend on gameplay actions and may give you just the right push for just a specific strategy you've chosen at the right moment. The sheer number of Policies towards the end of the game may give you pause come the next opportunity to switch...