In the SF RPG Universe, various die rolls determine how long players must wait for a ship to a given destination. From Section 32.4 of the GM Guide:
A Green jump route is a well-travelled commercial lane with passenger and freight service occurring daily (or more often). If a character or party wishes to travel this route, roll percentile dice to determine how many hours he must wait for a ship with available space.
An Amber jump route is an infrequently travelled commercial lane traversed by freighters and an occasional passenger vessel. Roll two dice to determine how many days a character must wait for available space on this route.
A Red jump route is a rarely travelled course traversed by a few exploratory and resupply ships. Roll percentile dice to determine how many days a character must wait for available space on this route.
So we must wait 1–100 hours for a green route ship, 2–20 days for an amber, and 1–100 days for a red. Or in other terms:
For example, in the
campaign Wars
and Rumors Of Wars
, the planet Nova Eŭropo (in the
Beedee system) has 3 green, 5 amber and 7 red interstellar
routes. The math is as follows:
| route | number | per 10 days |
|---|---|---|
| Green | 3 | 7.2 |
| Amber | 5 | 5 |
| Red | 7 | 0.7 |
| Total | 77.7 | |
So we have about 12.9 ships taking off in a 10 day period, or about 1.3 ships per day.
But that's just interstellar ships. Nova Eŭropo also has two green and one amber route to other planets and moons around Beedee—another 4.8+1 = 4.9 ships every 10 days, for a total of about 17.8 ships every 10 days, or a little more than one ship every 13 hours.
This is based on assuming that waiting 2–20 days for an amber-route ship means one every 11 days. This isn't quite accurate; 11 days is the average wait. Nonetheless, mathematically speaking it should work out about the same.
But wait! We're still not done. According to 25.5:
Orbital [spaceports] have a shuttle service to the world's surface; the number of flights per day equals the square of the Spaceport Class.
That means spaceports of Class 1–5 have shuttles down to the planetary surface:
| spaceport class |
flights per day |
time between flights |
|---|---|---|
| 1 | 1 | 24 hrs |
| 2 | 4 | 6 hrs |
| 3 | 9 | 2h40m |
| 4 | 16 | 90 min |
| 5 | 25 | ≈1 hr |
For Nova Eŭropo, that's another 16 flights per day, or 160 flights per 10 days. That means a total of 177.8 ships per 10 days, of which 160 are shuttles. In a given day, you can expect 18 ships to depart, of which 16 are shuttles to the planet's surface.
This assumes one orbital spaceport per planet. Larger planets, expecially ones with populations spread out over a larger proportion of the planet's surface, could be expected to have two, three or more orbiting spaceports. In such a case, we could expect interstellar routes to be spread out over the existing spaceports, with shuttles between the orbital platforms. Red routes, being primarily industrial, might be confined to one (industrial) spaceport, while green and amber routes would be spread out among passenger-oriented ports.
Note that this also assumes a given planet is the primary spaceport in the system. It's up to individual GMs to decide if interstellar flights can leave from other planets in the system, or whether passengers will have to take interplanetary flights to the primary planet first.