Civilization V has five different paths to victory.
Domination Victory
- Main article: Domination victory (Civ5)
In vanilla and Gods & Kings, you achieve a domination victory if you are the last player in possession of your original capital. You do not have to wipe out all other players entirely! It does not matter who controls the other capital cities: you can, for example, let another player take all the other capital cities but yours and then take their capital, at which point you win immediately. Also, if two other players capture each other's original capitals, you will win the game even if you weren't at war with either of them.
Note that the original capital city of a civilization can never be completely destroyed; it can only be captured. (Exception: You play the "One City Challenge".) If your capital is captured, another one of your cities will be assigned as the current capital. The current capital can, however, be destroyed and does not count towards the domination victory.
In Brave New World, you must control all opposing players' original capitals to achieve a domination victory.
Science Victory
- Main article: Science victory (Civ5)
To achieve a science victory, you must build and launch a spaceship. In order to do this, you need first to complete the Apollo Program project, and then you must reach far enough in the technology tree to be able to build the components of the spaceship. All of the necessary technologies for this are in the Information Era (Modern and Future Eras in vanilla), and require developing practically the entire tech tree.
Once you have all the required components of the spaceship (or as they become available), you can assemble them at your Capital. The spaceship will be automatically launched once assembled.
In Brave New World, it appears that the tech development in the later Eras has been considerably slowed (more Science required for each tech), probably to allow for longer time to play with all new late-game features introduced in the expansion.
Cultural Victory
- Main article: Cultural victory (Civ5)
Cultural victory is achieved by filling out five trees of social policies and completing the Utopia Project. Each tree has 5 policies, so in order to win you must have acquired at least 25 social policies in 5 different policy trees, for a total of 30.
Social policies are acquired with Culture, with the cost increasing for each new one. Also, founded and annexed cities increase the amount of Culture needed depending on map size, which makes this path very hard for large empires. To work around this issue, you can limit the foundation of new cities and, when capturing other players' cities, you can make them puppets instead of annexing them.
Cultural Victory in Brave New World
In the Brave New World expansion pack, Cultural victory conditions change dramatically, and we have what appears to be a "Cultural Domination" victory. The task is to use the new Tourism game mechanics to influence all other civilizations still in game and achieve at least the Influential level of cultural influence with each one.
Based upon the difference between a civ's Tourism and others' Culture, there are six possible stances: Unknown, Exotic, Familiar, Popular, Influential, and Dominant. The difficulty is to increase your cultural influence from Tourism with other civilizations, while at the same time protecting your own civilization from their influence using Culture.
Diplomatic Victory
- Main article: Diplomatic victory (Civ5)
Diplomatic victory is achieved by winning a vote in the United Nations. To win the vote, you must have the majority vote, and in order to gather more votes, players can become allies with City-States, or return captured cities to defeated AI players.
The player who built the United Nations first has two votes instead of the usual one, giving them an extra edge when voting. Every civilization leader will vote for another civilization that liberated his capital (in which case this leader will get the vote). City-States will only vote if they are allied with a civilization or a civilization liberated them in the past, so a common way of winning would be allying with the required amount of City-States on the turn just before the UN vote happens.
Diplomatic Victory in Brave New World
The Brave New World expansion has made changes to the Diplomacy feature. The United Nations is not a buildable Wonder anymore - instead it develops automatically from the World Congress when a Civilization reaches the Information Era or at least half of the world's Civilizations reach the Atomic Era. At that point, a new automatic vote starts every 20 turns: the vote for the World Leader. The conditions for winning this vote are pretty much the same as for winning the vote for any other resolution, except for a minimum number of votes required is based on number of civilizations and City-States.
Time Victory
Time victory is achieved by the player with the highest score by the end of the time period, assuming that no one has achieved any of the above victory types. The deadline for a time victory is usually the year 2050 AD, but it is possible to change it to an earlier year or a predetermined number of years. Note that, on standard speed, 2050 AD occurs at turn 500, making turn 499 the last turn you can play before this victory occurs. It can be very easy to lose a game if you mistime, say, your final spaceship part, if you don't have a score lead.
Scores are based on the amount of gold in the players' treasuries, the number of resources they possess, the amount of land they own, how many technologies they have researched (as well as amount of times you've researched Future Tech), the number of wonders in their cities, their total city population, the number of cities, and how many military units they control. It is possible there are more factors which contribute to the score, but those are the common ones.
This form of victory is a kind of Stalemate. Remember you can always disable this victory type before starting the game.