Since there's been a lot of talk about jump lately, I though I'd share how I figure Mis-Jump chances in play. The following is a hybrid from MT and TNE, but can be used with any of the systems.
|Showroom floor is 0; JD's WV can be reset to 0 by replacement with New JD|
|+1 per rebuild|
|+1 per 10 years service since last rebuild|
|+1 per field repair since last annual maintenance|
|+1 per year since last annual maintenance|
|+1 per major damage since last annual maintenance.|
|rebuild counts as annual maintenance.|
|Levels of success:|
|Failure*||+1 to +3 (nominally +2)|
|Crit Failure*||+2 to +4 (nominally +3)|
|* Under MegaTraveller, roll mishap, 2d for failure, 3d for crit failure, one die less if was cautious attempt. mishap level becomes penalty:|
| AM is Astrogation Success Modifier|
EM is Engineering Modifier
|Level of Damage:||Mod|
|Superficial: No effect on performance||+1|
|Minor: Reduced performance||+WV|
|Major: Shut down by damage||N/A|
|Damaged during Field Formation||Automatic MisJump|
|Damaged During Zuchai Crystal Charge-up Warning Light**|
|** Warning Light means You may: discharge crystals elsewhere, and re-charge (Fuel still used up, but don't jump); OR use existing charge, and take the automatic misjump.|
|Gravitic Disturbance Band||Mod|
The actual Check and Results
|To check: roll 2d for AdjWV or less.|
| AdjWV = WV + AM + EM + GM + LoDM|
If misjump occurs, roll 1d, plus 1d per 4 points by which roll was made
|Jump Mishaps (adapted from MT/SSOM)|
|2-||Trivial: Warning lights, or visible distortions, or 1d6 HOUR relativity error, or other totally trivial stuff.|
|3+||Superficial:||Jump Relativity Error: 1d6+4 days in jump, same time passes in N-Space, but roll secondary effect.|
|7+||Minor:||Jump Relativity Error II: 2d6+2 days in J-Space, and 1 secondary effect (which see, below)|
|11+||Major:||Jump Error: Classic Mis-jump occurs, and 1 secondary effect.|
|15+||Destroyed:||Ship will be destroyed. Results up to GM.|
|19+||Destroyed II:||Totally Goners: Go see god(s), devil(s), etc.|
|Roll 2d6 if directed here, and modify by 1 away from center for every full 10 points of AdjWV; note that a Superficial mishap means any un-adjusted roll of 6 or less has no effect.|
|0-||2d6 years pass in N-space during Jump|
|1||1d6 years pass in N-space during jump|
|2||2d6 Months pass in N-Space during jump|
|3||1d6 Months Pass in N-Space|
|4||3d6 days pass in N-Space|
|5||2d6 days pass in N-Space|
|6||1d3+6 days pass in N-Space|
|7||Visual Distorion: everything is shimmering|
|8||Minor Nausea: Easy Endurance to remain functional|
|9||Moderate Nausea: Average End to remain functional|
|10||Major Nausea: Difficult End to remain funtional, Easy Determination(TNE:Willpower; T4: End) to avoid injury|
|11||Critical Nausea: Formidable End to remain functional; Difficult Determination to avoid injury|
|12||Lethal Nausea: Impossible End to remain functional Formidable Determination to avoid injury|
|13+||Lethal Nausea II: Impossible Determination to avoid injury; Nobody remains functional!|
By haing most misjumps 95% or so) simply be time dialation/distortion, commerce is not impeded by the average WV of 3 or less; the true "Where the $%^& are We???" becomes much less common. Trade and Commerce can be reliable even with a J-1 when less than 8% go awry, assuming careless crews.
Also, highly skilled crews can, using my misjump calculations, nurse along ships with WV's in excess of 3, with little problem under MT or TNE; T4, change the success mods table to be -1 mod for success, -3 for crit success.
The secondary effects I seldom roll; I just "feel" for it [note to PN: All the time dialations over a week have been random rolls, not GM cruelty] with an eye towards storyline.
Also, I usually impose a 1 point penalty for a previous misjump until an inspection is made; normally I just have one of the following problems:
The first: They are 0.5% of Jump Drive Volume, at 4MCr per Ton displacement, and I assume them to mass 10 Tons per cubic meter (thus they mass 0.675 tons, and take 67.5 Litres per Td of Jump Drive). The volume is from High Guard; the mass from my common sense, and figuring what felt right out of MT's 27T per 13.5 KL (TNE/T4: 0.7 Tm and 0.07 Td per Disp ton of JD). Only a yard or spare crystals will do to negate the modifier.
Deposits can be cleaned any time the Jump drive is cool... IE, anytime more than 24 hours after entering jump. Routine Engineering and Dex.
Hairline Cracks can be fixed with Lanthanum Alloy Solder, and EVA. Long (1d6*1d6)+1d6 man-hours per 100 tons hull displacement.
Jump Governor: Replace or re-program. Reprogramming: Formidable, Computer or Engineering, Int. Takes about a week. Fatefull, Hazardous, Uncertain.
Gravitics: I assume gravitics have some role in Traveller Fusion plants (after all, so many engineers get gravitics). So I assign some gravitics roll to repair the gravitics involved with the JD's Fusion Plant.
Also, I assume that Jump Drives operate by exciting a lanthanum (or irridium) hull grid to a certain minimum quantum energy state, then pulsing it in some pattern to "weave the tumble", then finally pushing it up to a high level. The energized grid forms a bubble around the ship, which keeps J-space approxamately 1m away from the hull, and also, the bubble has a minimum curve radius of 2m. As the energy bleeds, it can be monitored. Due to J-Physics, the bleed is almost trivial until return to normal space; when it drops below threshold, the bubble collapses and the ship returns to N-Space. The "bleed" is a quantum state change with a decay time of 1 week in J-space, and measured in Plank units in N-space.
As a side note, a player once used this to sabotage a ship: he snipped a path 4.2m wide in JUST the L-Grid, all the way around the ship, just behind the bridge, then hid in engineering (Type T patrol cutter, BTW). When the ship left dock, he overpowered the engineering crew, and triggered the jump drive. The ship was cut in half, then the aft (PC included) was hollowed out by the Jump Field. They found pieces fo the ship over a 10pc line.
Another Side Note: In my games, I assume that Irridium was used by the solomani and vilani for their early (J-1, J-2) jump drives, and heve became a very valuable metal. But it required half the spaceing interval, and thus 4x the area, of lanthanum, as well as 4 times the power (and thus drive mass and volume). This assumption was made to justify the use of irridium as the backing of imperial currency rather than lanthanum, which is more strategic. Also, I assign Irridium drives a 2 point bonus versus misjump chances, but they also take twice the penalties when figuring out how bad a misjump is...;-)
This document is Copyright ©1999 by William F. Hostman. All rights reserved except as noted. Traveller and Megatraveller are trademarks of Far Future Enterprises, and are used with permission. Permission is explicitly given to make copies of this document for personal use only.