Hyperspace

Hyperspace is actually a misnomer. While it appears from the inside that a jump via hyperspace causes the ship to enter a glowing void that it stays in for but a moment, in actuality a hyperspace jump causes the ship to dematerialize and spontaneously appear at the destination through the manipulation of fluctuations in the quantum foam.

Jumping

Calculation

Planning a hyperspace jump is a matter of hashing your current position and momentum with some known jump coordinates, to determine twenty numbers which can be used to calibrate the hyper drive for converting from one position to the other. Aside from the use of devices such as a jump calculator, this can be done with a DC 5 Items check and ten minutes, or eyeballed as a lesser action with a DC 10 Items check. The check is rolled secretly, trying an unsuccessfully plotted jump results in appearing in a completely random place within the hyperdrive's range, moving at a velocity of 1d6% the speed of light in a random direction.

As things shift around in space, a calculation is only good for ten hours before it becomes out of date, but you can plan in advance which ten hour period you calculate it for. You also need to be in roughly the right position in space for the calculation to be accurate, within 10 kilometers of where you planned to be.

A normal jump has an inaccuracy of 4d6 kilometers in a random direction from the desired destination. By spending 5 times as long calculating the jump, and increasing the DC by 3 (a jump calculator cannot do this), you may entirely remove the inaccuracy of the jump. Failing on this increased DC but succeeding on the normal one results in merely having the regular amount of inaccuracy, not ending up in a random place.

Multiple ships within 10 kilometers of each other who have the same momentum and matching hyperdrive speeds may share a single jump coordinate and jump at the same time to arrive at the destination in formation, even with the inaccuracy.

Returning to Realspace

When a ship reappears, it rapidly contracts into its full size, potentially being ripped apart by whatever it collides with. If it collides with solid ground, the ship, the ground, and the ship's occupants take 1d6+4 Noise damage with 5 demolition. If it collides with loose matter such as pieces of shrapnel of 1 kilogram or more, or gas like an atmosphere, the ship, the shrapnel, and the ship's occupants take 1d6+2 Noise damage with 2 demolition. When the ship reappears, it takes on the velocity that the jump coordinates were measured with.

Jump Coordinates

Jump coordinates are long numbers that correspond to a particular position and velocity relative to a planetary body or other object weighing at least 100 quintillion kilograms. Standard jump coordinates are recorded in orbit around planets, relative to those planets, so a ship jumping to the planet using those coordinates will appear above that same point on the planet, in that orbit. If the planet were to be moved out of orbit of its star (say, by someone using an enormous hyperdrive to jump it to another system), then ships using those coordinates would still appear in orbit above the planet, in that new part of the universe.

Jump coordinates do not have to be in stable orbit in space, they can be measured for all sorts of things, like inside a garage or moving at relativistic velocity through deep space just as easily, however those coordinates are not typically printed in a hyperspace coordinates tome as they are very hazardous or pointless for typical pilots.

If the anchor object that a jump coordinate is relative to is destroyed or split so that more than 10% of it is no longer with the rest, the coordinates are relative to its center of mass.

Hyper Drive Statistics

Hyperspace jumps are very fast, but appear from the perspective of the person using it to be pretty much instantaneous. Each hyperdrive lists its jump capabilities in the format "10000c/10ly", where the first number is its speed in multiples of the speed of light (from an outsider's perspective), and the second number is the maximum range of a jump.