Having a blast, but need advice.

[Darkrenown]

Machine parts - How do I get them?

Research industrial techs to get free MPs and the ability to make your own. You can also buy them, but you really need to be in the top 2 or 3 prestiege wise to have a shot at them before 1850/60.

What does negative manpower mean? I know that positive manpower is used to reinforce existing forces.

It means you have more armies than you can support, so convert more pops into soldiers.

What does negative research mean? I got a massive "research debt" from buying tech from Spain. Is this what is slowing down my research? Are my scientists trying to adapt to all the new things they've learned but don't understand?

Yes and yes. You might wonder what the point of tech trading is if you still have to pay RP for them. Well you get the effects of the tech ASAP and once you are producing more than 10RP a year you have nothing else to spent them on. Also, it's the only way to get every tech since there is not enough time to research them all.

What is the difference between clerks and craftsmen? I notice both can work in factories...which are better to have? Or do you need a mix?

A mix is best. You really want 3 craftsmen + 2 clerks per level of the factory.

Should you upgrade your workers to fill your factories?

To a point, yes. But keep workers in RGOs which produce things which are exoensive to import or are rare.

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