Keywords: CS: Výzkumník, DA: Forskning, DE: Forschung, ES: Investigar, FI: Tutkimus, NL: Onderzoek, NO: Forsking, PL: Badania, PT: Pesquisa, SV: Forskning
The Research button (microscope symbol at the bottom of the screen) takes you to the research area, where you can use Research Points (RP) to unlock new engines and engine upgrades.
In the research area you can view research from the current and previous eras. Use the numbers at the bottom of the screen to see each era.
The level of the Laboratory in your Train Station determines how quickly new RP are generated, and how many you can have before you must use them. Once you reach the limit, new RP will disappear. With a plus account or researcher, RP generation is 25% faster.
The last item that can be researched in each era is Coupling. Coupling allows you to haul goods with engines from previous eras. Example: You cannot haul Era 3 goods with an Era 2 engine unless you have completed research on Coupling from Era 2. However, you can haul any Era 1-3 good with an Era 3 engine, regardless of whether coupling for the current era has been researched. Coupling is very helpful, as it allows you to use powerful engines through most of an era, so you don't have to use the less powerful early engines, which would otherwise be the only ones available for the new resources.
Note that multiple couplings cannot be combined, so for example era 2 trains can never haul era 4 goods, even if both era 2 and era 3 couplings have been researched.
Hiring a Researcher
In the research screen, you can hire a researcher at a cost of 40 gold for 24 hours. The plus account also includes the researcher. If you need the extra RP generated by the researcher, it is usually a much better deal to spend the gold on a plus account (100 gold for 7 days + the other advantages), and not just buy the researcher.
In order to unlock research of something, it is only necessary to research engines/upgrades that are connected with a solid line. Engines/upgrades that are connected to a dotted line are not required to be researched in order to unlock later research. In Era 4 and later, there are some items that can be unlocked through different paths, which are marked with A and B (and Era 6 will have path C). In these cases you only need to fill one of the paths to unlock the item (e.g. engine Thor in Era 4 requires either Neptune or Horus).
It is helpful to unlock Coupling as soon as possible, but remember that it has no use before you reach the end of the era, i.e. Era 2 coupling is only useful in Era 3. You should aim at reaching Coupling in all eras, and make sure to upgrade your laboratory as needed. If you're close to completing coupling when a new era starts, it can still be a good idea to finish researching the coupling during the start of the new era, before you start researching the new era's engines.
If you have enough time before the end of the era to do additional research, try to finish researching the optional items. Even if you do not need the optional upgrades, a medal is available which awards 250 Prestige Points (PP) for completing research on all technologies in an era.
You can use the Laboratory page on this wiki to see how long it will take for you to reach the maximum number of RP. When you approach the end of an era, this info can help you save up your RP so that you can use the maximum RP possible on the first engine in the next era, immediately after the new era begins.