[douglas]

For ship experience, each enemy ship destroyed gives 1%, and each enemy unit or seeker group destroyed gives .1%.

For fleet experience, each enemy ship destroyed has a 25% chance of giving .1%, and each enemy unit or seeker group destroyed also has a 25% chance of giving .1%. No, that is not a mistake - unit and seeker groups really do give the same fleet experience as ships, yet another reason to avoid missile weapons.

All kills must be by direct fire weapons in order to gain experience.

The 25% figure is from a very long ago post repeating what Aaron said in an email, but the testing I just conducted seems to indicate the rate is actually somewhat lower, around 20%.