Making EM Guns Viable in Space Combat (3e)

[Fred Brackin]

Originally Posted by GURPS Fox

F
For one, it depends on the setting.

For example, one setting -the lovechild between the Sci-Fi Annos and Transhuman Space- only has HePlaR rockets and would have space EM guns with velocities of 10-15km/s, given that ships can't achieve more than 5Gs of acceleration and a general tech level of TL10 with things like TL11 computers and biotech. Most combat takes place in the orbitals of a planet or asteroid.

No. My example about the invasion fleet launching from Mars and being met halfway to Earth was from a big battle I did during the Spaceships playtest with _much_ more restricted tech than you describe but its that approaching through normal space giving days of warning that means battles will be fought at long ranges..

Attackers seeking to capture orbital structures won't begin with long range bombardment but defenders will seek to destroy the attackers as far from the orbitals as possible.

Oh and in either3e or 4e if you're seeking to achieve the performance you spoke of for your HePLar rockets you need to use generic Total Conversion thrusters. No species of realistic nuclear rocket will do.