Technology tree

In strategy computer games, a technology, tech, or research tree is a hierarchical visual representation of the possible sequences of upgrades a player can take (most often through the act of research). The diagram is tree-shaped in the sense that it branches between each 'level', allowing the player to choose one sequence or another. Each level is called a tier and is often used to describe the technological strength of a player. Typically, at the beginning of a session of a strategy game, a player will start at tier 1, and will only have a few options for technologies to research. Each technology that a player researches will open up one or more new options, but may or may not, depending on the computer game, close off the paths to other options. The tech tree is the representation of all possible paths of research a player can take, up to the culmination of said sequence.

A player who is engaged in research activities is said to be "teching up," "going up the tech tree," or "moving up the tech tree." Analysis of a tech tree can lead players to memorize and use specific build orders.

The Classic tech tree is the one where extensive research into new technologies must be conducted parallel to the progression of a game. Some real-time strategy (RTS) games as well as most turn-based strategy (TBS) games employ this type of tech tree. In these games, players typically have a 'command center', 'unit-training-facility' and 'research facility' at their disposal from the start, allowing them to both start research into more advanced technologies, or engaging in combat with enemies using the basic units (Warzone 2100, Mega Lo Mania, Master of Orion series, 'Civilization series, Space Empires series).

In some games, the requirement of an actual research facility is absent. In this case players can allocate research points, or in-game resources to purchase new technologies. In some games the allocation yields direct results, meaning that procuring the new technology isn't paired with allotted time for the research of said technology to complete.

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Wikipedia