Civilizations can no longer trade with technology, as in previous versions of the game, instead civilizations can carry out common technological enterprises. Two civilizations at peace can form a research agreement that requires an initial investment of gold and provides the two civilizations with a certain amount of science as long as they remain at peace.  Before the PC 184.108.40.2062 version of the game, civilizations were equipped with unknown technology after a series of twists and turns of uninterrupted peaceful relations. It is possible for a civilization to sign a research agreement just to get an enemy to spend money that could be used for other purposes; AI civilizations are programmed to sometimes use this tactic before declaring war.  British actor W. Morgan Sheppard delivers the story for the opening films of the original game and its expansion packs, quotes on the discovery of new technologies and the construction of tourist sites and the introduction of the player`s chosen civilization at the beginning of each new game.  The money you invest in the contract is lost. That`s not necessarily a bad thing – if you can go to war with someone, they`ll lose the money they could have used to defend themselves. If a peace treaty is signed, all units are immediately expelled from the territory of the other country (unless an agreement on the opening of borders is part of the treaty) and all cities that have been negotiated will be part of the territory of their new owners. A peace treaty lasts 10 rounds and, during the treaty, the two sides must not declare war against each other. One of the most frequent interactions.
You can enter into trade agreements with any nation with which you are not at war. All trade agreements last 30 rounds, after which they must be renewed. There are some remarkable improvements in this new patch version. By far the best is the return of the research surplus, which eliminates incredibly laborious micro-management of research to avoid waste. This dramatically speeds up the technology rate in the first 50 rounds of the game, because you have lost constantly on the cups because of waste with the search for any new technology. Thanks for these Firaxis, although I`m not sure I give recognition for a feature that obviously should have been in the release version of the game! I also like the move to the circus building: „I think these problems are directly due to the decision to make civ V a one-unit-per-tile game (1UPT). 1UPT allows a lot of flexibility in how you organize your army; But it only works if his army has an empty space to move in. We need an army smaller than the map. 1UPT led to small army sizes, which led to lower production and faster science, which led to the broken economic system that this game has now.
The Civ V combat was based on general tanks, but it doesn`t work well in a civ-style game. I tried to explain why it`s in this post: (In PG, In England, there are about 500 witches. That`s enough room for very large armies to maneuver (and yet things get pretty overloaded when you fight over London). There are only six witches in Civ V. What am I supposed to do there? It`s not even enough to build a real city! The English channel is only 4 witches and a hexagonal width, so you can shoot them with archers.