Jumpdrive = Jumpgate = Wormhole
Wormholes, Jumpgates and Jumpdrives all use the same mechanic based around
Charge represents the current state of the wormhole as per Gazz' suggestion about Honor Harrington esque wormholes.
Charge directly correlates to the mass currently able to move though the wormhole.
when a ship travels trough a wormhole the currently stored charge decreases by an amount proportional to its mass
for ease of understanding i'd make it an 1:1 correlation.
both sides of an wormhole connection share a single charge.
wormholes can be given charge by natural or technical means.
artificial means can be used for charging wormholes.
this is done by jumpdrive/jumpgate (wormhole) modules
they use energy and maybe some kind of special fuel to convert it into WH Charge.
natural wormholes have natural self-charging capabilities, so they recharge without external input.
artificially created wormholes have 0 self-charge.
wormholes have an self discharge proportional to their currently stored charge
self discharge = constant * current charge
this leads to an equilibrium state when self discharge = charge speed
the constant is derived from the distance the wormhole bridges and gets higher with the distance.
there should be some bonus when a wormhole gets charged from both sides (or a malus when not charged from both sides)
to make double-gate structures the most efficient setup.
and to prevent jumpgates being used as on-demand ways for capital ships.
worm hole modules can open new wormholes and transfer energy to already existing wormholes
ship-based WHM and Stationary WHM are no different in principle, they differ only in stats.
Ship based ones are in general trimmed for small size and big burst output, but have big energy needs.
so they need burst capacitors bound to them to provide enough energy to open a wormhole large enough for the ship to pass through.
smaller wormholes can be maintained indefinitely, proportional to the ships generator capacity.
balancing should be choosen so that the "stational" state for WHM is never strong enough for a ship to move through itself.
but it can be used as mobile jumpgate for smaller ships.
stationary ones have in general less throughput (max charge / time) per unit size than mobile ones, but are in general much more efficient.
they use less energy/fuel to accomplish the same connection as an mobile unit, but are too unwieldy for mobile usage.
Edit 29.4.2014 16:20
it should also take a few seconds to minutes for a jumpdrive to charge the wormhole up to usable levels (for the wormhole creating ship).
to include gazz' thoughts about a visible mark that precludes the arrival of the jumping ship without trapping the player inside the jump and force him to do either nothing or play a minigame or such things
Edit 29.4.2014 15:40
recharge times for the jump-capacitors should be substantial, to avoid constantly jumping with a ship instead of actually flying it
- as per outlander4's suggestion
wormhole connections can only be established without penalty if there is a "line of sight" between the source and target system.
the blocking radius is determined by the mass of the star.
if the line of sight is blocked by a stars mass the discharge-constant gets significantly larger proportionally to the distance inside the blocking field.
so if the connection line does only skim the blocking radius you may still can establish the connection, but with a large penalty to its capacity and lifetime.
- mass (gravity) near to the wormhole's mouth does increase the discharge constant.
this causes wormholes opened up next to large masses (such as planets, stations, asteroid fields) to have much lower capacity than ones opened in empty space
in this light calculating lagrange points in star systems could provide practical gameplay. wormholes opened there would be the most efficient
this would also contribute to strategy
you either can try to jump from/to an lagrange point for efficiency but predictable endpoints
or you jump to somewhere else at the cost of efficiency and recharge time