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The Color of Jumpspace

This is a light revision of an article that was originally posted to the pre-magazine Freelance Traveller website in January of 2006. This revision appeared in the July 2013 issue.

Sources of Inspiration: Various, principally including Larry Niven’s Known Space series (cite as [Niven]) and David Drake’s Republic of Cinnabar Navy series (cite as [RCN])

Purpose: Primarily cosmetic.

Discussion: As presented, Jump is generally a non-event lasting a week—a break between today’s episode and “tune in next week, same time, same channel!”. Additionally, most starship designs and layouts, as presented, place the primary control center adjacent to the hull, with direct-view capability—something that is, strictly speaking, unnecessary for realspace navigation, and useless or worse during realspace combat. Adoption of the rules presented here (possibly suitably modified for a specific Traveller ruleset) addresses both perceived flaws while doing minimal damage to canonical background.

We assume for discussion purposes that Jumpspace is a partly-psionic phenomenon—that in order for a jump to be successful, there must be at least one living sophont mind inside the jump field (note: the J4 X-Boat canonically requires a crew of one (1), even though transport to the jump point is handled by a separate vessel, and the X-Boat has no significant ability to prosecute or defend militarily; why then must it be crewed, rather than completely automated? This is why!). The mind in question need not have any “true” psionic ability—i.e., being a Zhodani noble instead of a Hiver confers no inherent advantage—but there must be a sophont mind present. We further posit that the sophont navigator must have some direct method of perceiving jump-related phenomena—i.e., electronic sensors cannot successfully relay a useful view of jumpspace to the navigator. (Compare the need in [Niven] for a living intelligence to monitor the mass detector in hyperspace.)

One more assumption: The majority of jump fuel is used to generate energy to insert the ship into Jump space—but not all. The remainder is used to maintain “jump grid” or “jump coil” energization. The energization pattern/level can be adjusted—in small degree only—while in jump, and this manipulation of the energization pattern can affect the length of the jump, within the plus-or-minus-ten-percent limit. (Compare the ability in [RCN] to adjust the rigging while in ‘sponge space’.)

To simulate this, we allow the navigator to roll 2D an arbitrary number of times, and calculate the time-in-jump based on the number and value of the rolls.

Jump Energization Results
Roll Result Roll Result
2 +10 8 -2
3 +8 9 -4
4 +6 10 -6
5 +4 11 -8
6 +2 12 -10
7 0    

Note: An alternative method would be to simply roll (2D-7+Nav)(-2). For higher rolls and higher levels of Navigation skill, this method allows values beyond –10.

Before jump is initiated, the navigator should state how many observation rolls will be made. Each roll, 2D+Nav skill, represents an observation of jump space for some amount of time, followed by an adjustment of the jump energization. Record the result of each roll from the table to the right.

Following each roll, the referee rolls a DIFFICULT task (or equivalent) to determine whether the navigator is able to make the next observation as planned. If the navigator is unable to make an observation, record a result of 0. The referee should determine the relevant skill based on what event the referee believes could interfere with the next observation. The referee should also record the number of missed observations.

At the end of the jump, the navigator adds up all of the results recorded from the observations made, and divides by the number of observations originally intended. Then, the referee adds the total number of missed observations to the navigator’s result. The result should be constrained to the band -10 to +10, and the final result represents the percentage difference between the time of this jump and the ‘standard’ one week (168-hour) interval.

Example: Enli has Navigation-3, and will attempt to fine-tune this jump while en-route. He elects to make seven observations (one per day). He has a DM of +3 (his Navigation skill) on these rolls.

Roll 1: Enli rolls a 3; DM+3 = 6, which is a result of +2. The referee rolls no event that prevents Enli from making his next observation.

Roll 2: Enli rolls a 10; DM+3 = 13, which is beyond the maximum result of -10. The referee rolls an event; Enli is jump-sick, and will miss the next observation.

Roll 3: Enli does not roll this observation, as he is sleeping off jump sickness. The referee rolls no event that stops him from making his next observation.

Roll 4: Enli rolls a 5; DM+3 = 8, which is a result of -2. The referee rolls no event that prevents Enli from making his next observation.

Roll 5: Enli rolls a 7; DM+3 = 10, which is a result of -6. The referee rolls no event that prevents him from making his next observation.

Roll 6: Enli rolls a 2; DM+3 = 5, which is a result of +4. The referee rolls an event; Enli is injured while assisting the steward with an unruly passenger, and is in sickbay being treated. Enli will not be able to make the next observation.

Roll 7: Enli does not roll this observation. Since this is the last observation before breakout, there is no need for the referee to roll an event.

Enli’s total is -12, divided by 7 intended observations is -1.71. He missed two observation, so -1.71 + 2 is 0.29 - the jump took 0.29% longer than standard (168 hours), or 168 hours 29 minutes 14 seconds. Had he not missed the two observations, and rolled results of 0 for them, he would have been able to shave the jump time by 1.71%, or 2 hours 52 minutes 22 seconds, resulting in a jump time of 165 hours 7 minutes 38 seconds.

(If the alternative method had been used, the results would have been the same, except for Roll 2; Enli would have recorded a –12 instead of –10. In that case, his total would have been –14, divided by 7 is –2, +2 missed observations is 0, and the jump would not have been improved—but neither would it have been made longer.)