The consensus appears to be that jumpships are a serious balance problem and it sounds like it may be a critical mass problem.Watch TV, Do Nothing wrote:It's probably currently impossible to defend any specific individual planet against a mature empire, since big empires can assemble jump fleets so overwhelmingly large that they will eliminate all planetary defense structures without taking appreciable losses and can only be realistically harmed by another jumpfleet of similar size or by a painstakingly-assembled starship fleet, which is unlikely to be able to catch said jumpfleet.
There's actually a solution: jump interference. It's used to limit offensive movement in Starfire. Or at least it limits offensive movements in the novelization and I assume it's from the game.
Basically, if you jump more than one ship some may collide. The more you jump the more chances for collisions. In that setting the average number of collisions for n ships should be the chance of two ships colliding multiplied by C(n, 2) or n!/2(n-2)! and since Anacreon is a computer game it can actually roll a collision chance for each combination of ships. The actual collision chance can be tweaked.
The result would be that any jumpfleet large enough to overwhelm any defense would suffer crushing attrition to jump interference every time it jumped while small raiding fleets would be largely unaffected. Since jumpships are, as I understand it, unique in their jump mechanic they must also be unique in their technology and other ship types don't have any lore reason to suffer the same drawback.