Science (Civ5)

==Introduction==
 Science is a game concept in Civilization V which represents the research power of your civilization. Unlike other stats like or , it has only one use: the acquisition of new Technologies. This, however, is paramount for your progress in the game, because technologies unlock buildings and improvements that allow you to access resources and produce almost everything else, and they also advance your military, allowing you to fight more effectively. And of course, it is one of the main paths towards winning the game, via the Science Victory.
== Scientific Mechanics ==
As with most Civilization games, your scientific progress is measured in Science Points (SPs), also known as Research Points (RPs). They are generated by various sources and added to a total pool, which contributes to your current research project. The project toward which your civilization turns its research efforts is chosen from the available technologies in the tech tree, and may be changed at any point (without losing the progress you've made with the tech you abandoned). The discovery (development) of each technology requires a certain amount of SPs, which grows the more you advance through the tech tree, and which also depends on game speed, and the current size of your empire (number of cities you control). Besides that, each technology has one or more earlier technologies as prerequisites - thus the concept of a tech tree. The only techs without prerequisites are Pottery, Animal Husbandry, Archery and Mining - the ones first available for research in the very beginning of the game.*
The research process is automatic, and starts once you set up your - this means that you're constantly researching something throughout the entire game. The more SPs you contribute each turn for research, the faster you are going to discover the current technology. After you discover a technology, you gain all its benefits, and the game will prompt you to select the next one to be researched.
As mentioned above, you don't need to completely develop each technology before going to the next one - you can make some progress towards one, then change to another, if the strategic situation calls for it. Later, you'll come back to the first technology, and your scientists will resume from where they stopped.
=== Tech Tree and Civilization Eras ===
All technologies in the game are organized into a "tree," with each tech "connected" to one or more higher-level techs. Those higher-level techs cannot be researched before you finish all lower-level techs that connect to them directly (a process known as "unlocking"). So, you can neither research nor gain in other ways technologies you haven't unlocked - keep that in mind when planning your technological development and which techs you're going to research next!
The technological tree is also divided into eras, starting with the Ancient Era and finishing with the Information Era. These eras are a broad representation of the general level of development of your civilization, both from historical and game viewpoint. Each era includes a number of technologies, divided into two tiers; all techs in certain tier require roughly the same amount of SPs, and the general amount of SP progresses gradually from left to right. Those of Tier 2 (the rightmost tier) are almost always connected to Tier 1 (the leftmost tier). In other words, techs of Tier 1 of a certain era are almost always prerequisites for Tier 2 techs of the same era. There are notable exceptions, however, and in many cases you may leap tiers to progress faster to the next era.
Your civilization always starts in the Ancient Era (unless you start a custom game from a later era). To progress to the next era, you either need to research all technologies included in the previous one, or a single technology from the next era (after unlocking it of course). The era you are currently in determines a number of other gameplay effects, such as the exact amount of and you receive from friendly City-States, or what Social Policies you have access to.
Note that passing into the next era is an important achievement for a civilization, and is marked by a special announcement. Keep an eye for these announcements to track the progress of your rivals!
For a full list of technologies, see here.
== Producing Science ==
=== Population and Buildings ===
The main source of SP in the game is your population. Each Citizen in each city in your empire (even the Puppet cities) automatically contributes 1 SP to the total. On the other hand, each city (even Puppet cities) increases cost of new technologies by 2%! Therefore, if you want to maximize science production, it's better to have a small empire with heavily populated cities than a large empire with many cities, each one having only 3-4 Citizens. Of course, the best thing is to have a large empire with large population. 
The second source of SP are the science buildings. However, most of these base their contributions on the number of citizens in the city where they're built, which means population again matters. For example, a Library is more effective in a city with 20 Citizens (providing +10 SP), than it is in a city with 6 Citizens (providing only +3 SP). Certain Wonders also produce or enhance science, as shown below.
Buildings that provide science
Building	Era	Science 	Requirements
 	 	+1 Science for every 2 Citizens 	
 	 	+33% Science, +2 Science on jungle tiles worked by the city	, requires a Library, Paper Maker, or Royal Library
 	 	+50% Science 	, requires a mountain adjacent to the city
 	 	+3 Science, +1 Science for every 2 Citizens 	, requires a University or Wat
 	 	+4 Science, +50% Science 	, requires a Public School
 that provide science
Wonder	Science 	Requirement
 	+3 Science, free and provides one free technology	
 	+3 Science, +50% Science 	Requires a in every city
 	50% more Science from research agreements 	
Requires Rationalism ()
 	+3 Science, and provides one free technology 	
Requires a in every city
=== Scientist Specialists ===
A number of science-oriented buildings have slots for Scientist Specialists. Assigning Citizens to work in them provides +3 Science each to the city's base output.
===Terrain===
Normally, terrain isn't a source of Science. The only type that has inherent science potential is jungle, but only after you build a University in the city which controls it (which doesn't happen before the middle game).
Many Natural Wonders produce Science, and could be extremely beneficial to your empire in the early game, providing additional science when no other sources are yet possible.
Finally, the Academy improvement adds a good amount of Science to a tile - again very useful in the early game (and also later - the initial amount increases with certain technologies).
Terrain features that boost science
Feature	Bonus
 	+8 Science, +10 Science with , +12 Science with , +16 with from the Freedom Ideology
 	+1 Science with from the Rationalism Social Policy Tree
 	+2 Science when worked by a city with a
===Other Sources===
The following additional ways to boost Research are available:
* Opening trade routes with other civilizations; each route will contribute some SPs, based on the number of technologies the other civilization has discovered that you haven't.
* Using up a Great Scientist via his special ability. This contributes immediately large number of SPs, equivalent to the cumulative science output of your empire for the past 8 turns (on Normal speed, otherwise a coefficient is introduced).
* Conducting research agreements with other civilizations. Again, this contributes a fixed number of SPs towards your current research effort. Note that if you earn more than enough points to finish researching the current tech, the extra points are automatically applied to the next technology in your queue, or another random technology available for research if you do not have one queued up. The same is valid for the Great Scientist.
There are also ways to gain "free" technologies:
* Stealing technologies from other civilizations via spying. Note that you're limited to the technologies the other civilization has discovered, and you haven't, but have unlocked and available for research.
* Constructing certain Wonders.
* Finishing the Rationalism policy tree.
The following Social policies and Ideological Tenets also boost Science:
 that provide science
Policy/Tenet	Tree/Ideology	Era	Requirements 	Effect
 	Patronage 	 	Philanthropy 	City-states provide 25% of their Science to you
 	Rationalism 	 	none 	+2 Science for every specialist
 	Rationalism 	 	Secularism 	+17% Science to Universities, +1 for s
 	Rationalism 	 	Free Thought 	Boosts Science gained from Research Agreements by +50%
 	Order 	 	Two level 1 Order Tenets	+25% Science to Factories
 	Autocracy 	 	none 	Spy tech stealing rate +50%
Notes:
* Adopting Rationalism gives you a +15% Science while your empire is Happy (+10% Science in ).
* Adopting all policies in the Rationalism tree will grant 2 free Technologies (1 free Tech in ).
* Completing Order gives you +2 Science in every city (in vanilla and ).
* Completing the Freedom policy tree doubles production from Great Person tile improvements, including the Academy (in vanilla and ).
** This effect is transferred to the New Deal Freedom Tenet.
=== Science Conversion ===
After researching Education, your cities gain the ability to convert 25% of their current  into Science. Just assign this ability in the Production function of a city, and it will start producing science, adding points each turn according to its production potential!
Additionally, note that all Science production in Puppet Cities suffers a 25% penalty.
== Strategy ==
As mentioned above, scientific progress is vital for your empire, especially on higher difficulties, even if you don't pursue a scientific victory. Good technological progress allows your army to gain an edge thanks to superior military tech; it gives you higher chances at completing Wonders because it allows you early access to them (and as we know, Wonders are completed on a "first build-first serve" basis), and it unlocks all buildings necessary for the other types of victory.
 Science depends first on , and then on buildings, most of which base their bonuses also on population. So, having a large population is a key to producing lots of Science.
Use every opportunity to extract science from terrain - if you have lots of jungle tiles nearby, DON'T CUT THEM DOWN, unless you absolutely must! Each one will boost Science as soon as you build a University in the city controlling it. Also, when you gain a Great Scientist, build its tile improvement - the Academy. And search for those Natural Wonders that produce Science, and try to build a city nearby!
Technological progression is paramount for everybody in the game; but just as important as producing the Science is how you use that science, or rather (since science only has one use - discovering technologies) in what order you discover your technologies. You should have a strategy for that, based on your current development strategy, the current circumstances of your empire (being low on , , or another commodity, or being threatened by a neighbor), and finally on the type of victory you're striving for.
A very important technique you need to master, if you want to be successful, is "leapfrogging" techs. Because of the way the tech tree works, you are actually able to move up the tree without researching every single technology! This may be used to gain early access to the benefits of a key tech, including the ability to construct certain World Wonders ahead of the competition. To achieve that, check the tech you want in the tree, then follow back the lines that connect to its left side - they will lead you to the immediate prerequisites for the technology. Repeat that for these techs too, until you establish the necessary path to your current tech state. Then work consistently towards the target tech, leapfrogging the others along the way. Afterwards, go back and research what you skipped. (It's not advisable to leave big technological gaps in your tree, as this will almost certainly backfire at an inopportune moment.) A sign of the importance of this technique is that the computer AI always uses it, especially in the beginning of the game.
Science is practically required for 2 of the 4 victory conditions: Science Victory and Diplomatic Victory. For the first you'll need to build a Spaceship, and its 4 parts are unlocked via 4 of the last technologies in the Information Era (or Future Era in vanilla Civilization V) era. For more info on this type of victory, see Science victory.
In the second case, there is a Wonder needed to trigger voting for a World Leader: the United Nations. This wonder is unlocked by the Globalization technology, which is also one of the last in the last era. Although, its prerequisites allow you to rush to it by skipping a good deal of the Atomic Era and Information Era technologies. Without this Wonder, it's impossible to win a Diplomatic victory (the voting will never start), and the others won't probably build it, if they see you have large influence with city-states.
Note that the United Nations isn't a Wonder anymore in the Brave New World expansion pack, but develops automatically from the World Congress, so the above isn't valid - you won't need that much science for a diplomatic victory. Still, the Globalization technology remains extremely valuable for winning this type of victory - rush straight to it!
Finally, for a Domination victory, you'll need a competitive army, capable of defeating all other civilizations. Again, late-game military technologies will be required for that.
* In fact, they DO have a prerequisite: the Agriculture technology. But the discovery of this tech is the very basis of civilization, the one requirement for a barbarian tribe to advance to this new status, so we consider that every civilization starts with Agriculture already researched.
== See also ==
* Science in other games