This strategy only works for large/gigantic galaxies, right? Otherwise it seems that colonization will have been completed before you've researched the techs required for planetary invasion. (It's a cunning strategy, I just want to make sure I understand the limitation
Yes your right, that is based on a gigantic map. But also based on a very research biased game. i fill my home planet with 1 entertainment centre, 1 factory and the rest labs. The next planet is 1 factory and the rest labs, then i alternate planets between an economic world and research world. Only 1 in every 5 planets is soley a manufacturing world. Using this technique gets you through the techs very quickly. my first few techs generally are as follows,
Sensors 1
Hyperdrive - New Propulsion Techniques - Ion Drive
Xeno Communications - Universal Translator - Diplomatic Relations (for diplomatic translators)
Then i get to laser 5 as quick as i can.
next is the planetary invasion tech and then onto the terraforming techs to get Aphrodisiac.
I don't need anything past ion drive for a while cause i often take the plus 2 speed bonus, depends on who i am playing.
This works well for me on challenging and tough, you will suffer in your economy for a while and selling techs off to other races is a must, just don't sell research techs and diplomacy techs. If you sell them research techs your price per tech will drop. And you need the diplo advantage to get out of any wars that get too hot. When possible get through the diplo techs asap.
At painful i have not had as much success with this strategy, i find that i get into too much debt too quick.
Hope this helps....