Technology, or tech for short, is useful when technological development is important to a game. There are several ways to use it.
One use of tech is to track the results of research.
You do this by setting the initial tech of a side to (say) 0,
then requiring a certain tech (say 60) in order to build a desired type.
If a research action adds 1 to a side's tech, then it will
take 60 research actions to gain the necessary level.
The number of turns, of course, depending on how many actions
the researcher can do each turn, and how many researchers
are available. So for instance, 10 researching units results
in the work being done in 6 turns instead. You can limit this
schedule acceleration by setting tech-per-turn-max
.
Another use of tech is to differentiate sides.
Suppose you want to do a game involving earthlings and space aliens.
The aliens can have satellites overhead that earthlings don't even
know are there, they have equipment earthlings couldn't use even if
they were able to capture it. However, earth scientists might learn
something from it. To do all this, use tech-to-see
and friends.
Tech is fundamentally tied to unit types. However, many games have
a number of unit types that share technology. For instance, advances
in bomber technology usually lead to advances in fighter and surveillance
aircraft. The tech-crossover
table is available for this purpose.