It doesn't technically stop you, as you need to have all techs discovered before moving on to future tech. However, I rarely get beyond FT1 (If I get that far) as I shut science off and just rake in the gold. Not that I need it, then.
If you haven't researched an optional tech, the computer will usually suggest the cheaper, older techs later in the game. At least, that's been my experience.
If you haven't researched an optional tech, the computer will usually suggest the cheaper, older techs later in the game. At least, that's been my experience.
