A nation starts with very low skills in mining, farming, construction,
etc... These skills can be developed by investing money or metal
in technology research. This investment is made in the budget report.
Increase in technology depends on how much metal and money you invest
each thon. Metal will increase technology proportional to the
4/3's root of the amount of metal invested;
money will increase technology proportional
to the square root of the amount of metal invested
Other benefits of technological R&D are that with each new technology
you develop, you can gain certain things. For example, fire
increases mining ability, decreases the mortality rate, and increases
farming ability. As well, you can gain the ability to draft
new types of armies.