Getting back to warping restrictions for a sec, I have one more idea to throw out there:
What if ships with FTL drives exerted some type of interference field around them, proportional to their mass, which would cause enemy ships to be unable to engage FTL? Imagine an invisible bubble around every ship. If one ship's bubble comes in contact with another ship's hull, then the would not be able to warp unless it exited the bubble. Basically, if you get too close to a ship, you won't be able to run away unless you get far enough away from them. The interference could also prevent ships from warping in, so a large ship would not be able to warp in right on top of a small ship, and vice versa.
For example, let's say you have a large, heavy cargo ship giving off a wide field of warp interference that a group of pirates in small fighters have targeted. Their ships are small and light, so their warp interference bubbles are much smaller. They will have to get in close to prevent the cargo ship from fleeing, but they cannot warp to a point within the cargo ship's interference field. So they have to warp in somewhere far away from their target, giving it enough time to see them and try to escape- unless the smaller ships can reach it it in time, or disable it. On the other hand, maybe the cargo ship is better armed than the pirates thought. It could fight back, and the pirates would have to retreat. They would have more distance to cover until they would be out of the field, compared to the transport, but they would also be faster and more maneuverable. There could also be a minimum amount of strength required for a ship to prevent another ship from warping (~5% of a ship's mass, from one or multiple ships) so if enough smaller ships are destroyed, they wouldn't be able to prevent a large ship from escaping. This would also keep a tiny ship from landing on a huge ship and preventing it from entering warp.
It's similar to some other ideas that have been floating around, and I think it's simple enough to be flexible and lead to some interesting scenarios.
That's a hard cap on jumping, what if we take a page out of games like Battletech and Full Thrust and make that warp bubble, rather than outright interdiction, which would dissuade
closer ranges, and instead make it a damage gradient.Hypertrophic Reactions/Interstitial Feedback:
while powered up and ready to jump, FTL drives create an area of unstable space that violently interacts with other active FTL interfaces; radius of this effect and its corresponding hypertrophy gradient (i.e. damage falloff over distance) varies between each style of hyperspace mechanism, but a general rule of thumb is that a bigger drive creates a larger, more lethal interference envelope when charged for transit. Jumping inside such an 'interdiction zone', depending on the relative size between offending vessels, has often spelled the doom of both the blockade runner and the interdictor alike. At best, either party can expect their drive cores to be ravaged by the interstitial feedback, if not large sections of the drive compartment(s) to be irradiated or even slagged by the outpouring energy of such destructive waveforms, roughly described by a popular physicist as "a small pocket of the universe unfolding inside the hyperspace engine's workings"
the downside to this 'hyperspace interdiction' method is that simply charging an FTL drive for a jump requires a massive and sustained power input, meaning that an 'interdictor' vessel isn't doing much else with its powerplant besides keeping its FTL core up and runningSignal Flare:
worse than merely soaking a large amount of output from local reactors, an active FTL drive is easily detectable with the most basic commercial subspace detection equipment nearly halfway across most solar systems (such outposts can easily be operated by a single spacer in a minimalist setup, much like the archaic hobby of HAM radio operation).