[ Freelance Traveller Home Page | Search Freelance Traveller | Site Index ]

*Freelance Traveller

The Electronic Fan-Supported Traveller® Resource

The Color of Jumpspace II: Jump Sickness

This article originally appeared in the December 2014 issue.

Jump Sickness is mentioned in several Traveller sources, but only as something that happens, and not usually to player-characters. However, it offers game opportunities:

Obviously, the referee can whip up some jump sickness by fiat at any convenient and appropriate time (it wouldn’t do, after all, to suddenly turn up jump-sick when you’ve been on-planet for three days), but that sort of thing often seems to lead to a perception that the referee is trying to railroad things. It’s much better, in that respect, to let the dice decide, all open and aboveboard.

There’s little, if any, canon on when or how jump-sickness occurs, save that it’s (obviously) connected with jump. For maximal opportunity to use it, assume that jump-sickness may occur on jump entry, jump exit, and, if you use the jump observation and adjustment rules outlined in “The Color of Jumpspace” (July 2013), at any adjustment to jump energization.

There are three elements to jump-sickness: susceptibility, severity, and duration.

The more susceptible to jump-sickness a character is, the more likely it is that the character will be affected by jump-sickness at any given opportunity. In Classic Traveller, MegaTraveller, Marc Miller’s Traveller (T4), Mongoose Traveller, this is a throw of 2D for END or less. Regardless of the actual value of END, a throw of 2 means that the character does not get jump-sick (“critical success”), and a throw of 12 means that the character does (“critical failure” – the severity and duration are both automatically maximum). In Traveller5, roll for C3 or less, using the same number of dice as for creating the character. If you roll all 1s, this is a critical success; if you roll all 6s, this is a critical failure. In Traveller: The New Era, roll 2D-1 for CON or less (if you roll 2 or 12 before subtracting, treat those rolls as critical success or failure, respectively, as above); in GURPS Traveller, roll 3d6 for HT or less, with a roll of 3 being a critical success, a roll of 18 being a critical failure regardless of HT, and a roll of 17 being an ordinary failure if HT is 17+; and in Traveller20, roll 3d6 for CON or less (use the same critical success and ordinary/critical failure rules as for GURPS Traveller). There are no DMs for any of these rolls, regardless of system (but see the Optional Rule below). This is called the Susceptibility Check. If this roll fails, but is not a critical failure, note how much it fails by (e.g., if the character’s END is 12, and the roll was 8, note that the roll failed by 4). This is the failure margin. Divide the failure margin by the number of dice rolled (round fractions down) to get the severity modifier.
Severity is a general indication of how incapacitating the symptoms are. Jump-sickness does not affect everybody equally, and on different occasions may not affect the same character in the same way. Roll 1D6 and add the severity modifier. The symptoms for each level listed here are only examples; the referee should feel free to create other symptoms or sets of symptoms.
  1. Headache.
  2. Dizziness, or minor loss of coordination. The character finds it difficult to carry out ordinary activities, such as picking up small objects without dropping them, walking without stumbling, typing accurately on a keyboard, and so on.
  3. Minor seizure. Similar to petit mal epilepsy, the character engages in no activity and seems unaware of his surroundings.
  4. Nausea and vomiting. The character will not be able to eat or drink without immediately vomiting it up; for prolonged bouts, it may be necessary to feed and hydrate the character intravenously.
  5. Major seizure. Similar to grand mal epilepsy, the character experiences severe, uncontrollable muscular spasms.
  6. Unconsciousness.
Sometimes the symptoms will last longer than others. This is independent of how severe the symptoms are; one can have a headache that lasts for days, or be unconscious for only a few seconds. Roll 2D6-2 to determine how many time units the symptoms will persist, then roll 1D6 to determine what the time units are:
  1. seconds
  2. 10 seconds
  3. minutes
  4. 10 minutes
  5. hours
  6. 10 hours

If a new check for jump sickness needs to be made before the duration expires for a previous check (e.g., because the jump energization adjustment rules are being used), do the END/CON/HT/C3 check as per the rules above, but if it fails, do not calculate a severity modifier nor roll severity; simply go to the next level of severity, and re-roll duration. The new duration begins immediately; if it is short enough to expire before the original bout of jump-sickness, the character experiences a full recovery – the original symptoms no longer apply. On a critical failure, the character experiences the most severe symptoms for the maximum amount of time (beginning immediately, not prorated for the previous bout of jump-sickness). If the check succeeds, the original symptoms and duration continue unchanged; on a critical success, the character recovers immediately.

Optional Rule:
Even though generally higher END/CON/HT/C3 means generally better resistance to jump-sickness, some people may be unusually susceptible or unusually resistant to jump-sickness. To simulate this, do a Susceptibility Check as though for actually having a bout of jump-sickness, but regardless of the roll, calculate the difference between the roll and the character’s END/CON/HT/C3, and divide by the number of dice rolled (round fractions down). This number should be recorded as negative if the check succeeded, or positive if the check failed. For all future jump-sickness checks, treat this number as a DM to the roll. Note that if you are using this rule, critical success and failure (and the ordinary failure exception in GURPS for HT 17+ or in Traveller20 for CON 17+) are based on the unmodified roll; a Classic Traveller character with a DM -1 for this check does not experience a critical failure if he rolls a 3 (which gets modified to a 2).