[douglas]

Suppose you have a series of laser weapons, Laser I through Laser X and Advanced Laser I through Advanced Laser 5. Lasers require Lasers technology 1-10, and Advanced Lasers require Lasers technology 6-10 and Advanced Lasers technology 1-5. So, you can just research Lasers all the way to the end to improve your basic weapon, but beyond a certain point you need research in other areas to really get the best stuff.

You want everyone to start with Laser I weapons available in a low tech game, and Advanced Laser I in a medium tech game. Set the Start Level of Lasers technology to 1, and the Raise Level to 6. Set the Start Level of Advanced Lasers technology to 0, and the Raise Level to 1.

With these setting, a low tech start gives everyone 1 level in Lasers and none in Advanced Lasers, satisfying the prerequisites for Laser I. A medium tech start gives everyone 6 levels in Lasers and 1 in Advanced Lasers, satisfying the prereqs for Advanced Laser I (along with Laser I-VI).