Comment by m4rtink

I can imagine basically 3 classes of this:

Players can FTL, but big stuff (planets, stations) orbit realistically.

FTL only via gates or jump points, other flight only via realistic newtonian physics.

No FTL/no intra syste FTL (kinda like in Webers Honorverse SF series).

This third option limits playable areas for multiplayer games to a solar system or even a section of it (cislunar space or a gas giant + moons). And even with very advanced engines flights would still take hours or days. On the other hand this would present an interesting mechnics - once you do a burn, you know when you will arrive at your destination or encounter an enemy that already committed to a trajectory.

Then you join for the battle (or setup a battle program beforehand) before doing another burn (if you survive) & signing off again while the ship continues flying the trajectory.

Kinda like correspondence chess with hectic minutes of nuclear space ships trying to kill each other during encounters.