misjumps in Traveller Companion vs. Core rulebook

adzling

Banded Mongoose
So there seems to be a significant discrepancy in the chance of having a misjump when comparing the rules in the Traveller Companion to those in the Core rule book.

Core:
Astrogation: The jump needs to be plotted. This is an Easy (4+) Astrogation check (1D x 10 minutes, EDU), modified by the jump distance (thus, a jump covering four parsecs gives DM-4 to the check). If the check is failed, then the astrogator must plot the jump again. Astrogation can be done in advance (a jump is normally plotted while the ship is travelling out to the 100-diameter distance).

Jump!: Firing the jump drive requires an Easy (4+) Engineer (j-drive) check (1D x 10 minutes, EDU), modified by the task chain of the original Astrogation check and the following modifiers.
• Jump drive not maintained: DM-1 per month behind maintenance
• Using unrefined fuel: DM-2
• Still within the 100-diameter limit: DM-4
If this check is failed, then the ship misjumps.

Companion:
A Misjump occurs if the sum of the Effect achieved by the astrogator and engineer is 0 or less. This means that if one fails their check but the other makes theirs by a greater margin, the Misjump is averted, though in this case the effects of a Bad Jump should be imposed.
If the sum of the Effects is 0 or less, a Misjump has indeed occurred, and if both checks are failed a Serious Misjump has happened.

--
Using core rules the Engineer must fail his check (less than 4) for a misjump to occur.

Whereas with the Companion rules both the Astrogator and Engineer can succeed in their tests (target number 4 by default) but still have a misjump because their net effect was zero.

Clearly a misjump would be *far* more common with the Companion rules.

thoughts?
 

Arkathan

Cosmic Mongoose
The Companion rules are all optional.
You can always just rule that barely making both rolls, missing one, or net zero effect results in a bad jump vs misjump.
 

adzling

Banded Mongoose
Yeah clearly they are optional but:

1). they provide more granular details on jump outcomes, something that our game needs.

2). you'd think they would at least preserve the same chance of a misjump from the less detailed rules in core.

just interested to hear folks thoughts, thanks for yours
 

MongooseMatt

Administrator
Staff member
adzling said:
2). you'd think they would at least preserve the same chance of a misjump from the less detailed rules in core.

The way we look at it is this...

The Companion rules are indeed optional - but if they prove popular, they may well make it into a new edition (or an Update).

Hope that helps!
 

adzling

Banded Mongoose
Appreciate the insight Matt.

IMHO I think the detail in the core rules is fine for most times you jump.

However in specific circumstances more detail is needed.

Example: In our last session the PCs entire fleet of 5 ships was jumping after their target and the time of arrival of all ships would have a great impact on the potential encounter. In this instance the optional rules in the Companion offer the detail we needed to resolve this. However with the chance of a misjump so much higher in the Companion rules one of their ships misjumped 10 sectors and blew their jump drive. When comparing the outcome of the rolls between Companion and Core it was clear they would not have misjumped with core rules.

IMHO the best option would be to bring the misjump chance to parity between both the core and companion rules, with the companion rules offering more details. This would let the GM pick which one to use as appropriate (streamlined rules for most jumps, detailed rules for when they are needed).

I think a potentially simple way to achieve this is to leave the Core misjump rules untouched but slightly amend the Companion rules as follows:

"A Misjump occurs if the sum of the Effect achieved by the astrogator and engineer is 0 or less."

changes to:

"A Misjump occurs if the sum of the Effect achieved by the astrogator and engineer is -1 or less."
 

Condottiere

Emperor Mongoose
One viewpoint would be that a great astrogator can compensate for a mediocre engineer, and vice versa.

Though the default result should be the same, with either method.
 

Garran

Banded Mongoose
Honestly, I just see a lot of Astrogators running the calculations over and over until they have a really high Effect, so the Engineer could be playing whack-a-mole with the jump drive controls and they still get a net success.
 

Geir

Cosmic Mongoose
The thing that's not clear in my mind is if the astrogator knows he messed up. Otherwise it's always a positive DM and if the astrogator has time to try again and get a better result, then why not keep rolling all they way out to 100D.
It would be more fun as a task chain with Engineering or with what Megatraveller called 'uncertain tasks'.
(And why is the skill called 'Astrogation' not 'Astrogator' when most of the other skills match the Traveller that performs them - like 'Flyer', (but oddly 'Drive' and not 'Driver'), 'Gunner', 'Gambler', 'Pilot' (okay, that one works both ways)... (I actually like 'Astrogation' better but look up 'pendant' in the dictionary and there'll be a link to me...)
 

ShawnDriscoll

Cosmic Mongoose
adzling said:
So there seems to be a significant discrepancy in the chance of having a misjump when comparing the rules in the Traveller Companion to those in the Core rule book.
The beauty of having core rules and companion rules is that Referees can use the ones they prefer.
 

Condottiere

Emperor Mongoose
A really successful astrogation check would allow the engineer a larger margin of error.

What would force a recheck would be if for any reason, the agreed upon departure point is changed, similar to what would happen with a jump tape.
 

Rikki Tikki Traveller

Cosmic Mongoose
Geir said:
The thing that's not clear in my mind is if the astrogator knows he messed up. Otherwise it's always a positive DM and if the astrogator has time to try again and get a better result, then why not keep rolling all they way out to 100D.
It would be more fun as a task chain with Engineering or with what Megatraveller called 'uncertain tasks'.
(And why is the skill called 'Astrogation' not 'Astrogator' when most of the other skills match the Traveller that performs them - like 'Flyer', (but oddly 'Drive' and not 'Driver'), 'Gunner', 'Gambler', 'Pilot' (okay, that one works both ways)... (I actually like 'Astrogation' better but look up 'pendant' in the dictionary and there'll be a link to me...)

Making multiple checks is probably the 'normal'. I usually don't even make the players roll. BUT, in a critical situation, running from missiles etc. THEN the check is important and that is when they have to roll - one roll make ti count. If you fail the roll, do you have the time to redo the calculations before the pirate catches you or do you have to go for it???
 

adzling

Banded Mongoose
ShawnDriscoll said:
adzling said:
So there seems to be a significant discrepancy in the chance of having a misjump when comparing the rules in the Traveller Companion to those in the Core rule book.
The beauty of having core rules and companion rules is that Referees can use the ones they prefer.

The issue is not that there are optional rules to core.
The issue is that when comparing both rulesets the chance of a misjump varies significantly between the two.
If the chance of misjump was the same then you could use the two sets interchangeably, defaulting to the core rules and using the Companion rules when the situation demands more detail.

In the end we decided to alter the Companion's rules by adding in one word, to bring the chance of a misjump to parity.

Specifically:

"A Misjump occurs if the sum of the Effect achieved by the astrogator and engineer is 0 or less. This means that if one fails their check but the other makes theirs by a greater margin, the Misjump is averted, though in this case the effects of a Bad Jump should be imposed.

If the sum of the Effects is 0 or less, a Misjump has indeed occurred, and if both checks are failed a Serious Misjump has happened. All Misjumps are accompanied by the effects of a Bad Jump, and Serious Misjumps are accompanied by the effects of a Very Bad Jump. This is in addition to the effects noted on the Misjumps table below.

If a SERIOUS Misjump occurs, roll 2D on the Misjumps table below using the combined Effect of the Engineer and Astrogation checks as a DM."

Adding the word SERIOUS to the last paragraph above reserves the most dangerous misjump outcomes for when the Astrogator and Jump engineer both fail.
 

Arkathan

Cosmic Mongoose
A zero effect is a marginal success. I don't think a misjump should occur on a marginal success, unless there was a significant DM to make it a very mild misjump, but a bad jump would definitely be in order.
I'd argue that a marginal failure shouldn't have any chance of a major misjump. For an effect of negative 1, I'd start with a 6 and have them roll 1D to add to it, then consult the table, giving them a 1/3 chance to wind up a few parsecs away.
 

adzling

Banded Mongoose
Arkathan said:
A zero effect is a marginal success. I don't think a misjump should occur on a marginal success...

agreed, hence our change to the Companion rules for when a misjump occurs.
 

MonkeyX

Banded Mongoose
I tend to use the companion rules the first time the PCs jump into a new system or when dramatically appropriate.
 

Bense

Banded Mongoose
Garran said:
Honestly, I just see a lot of Astrogators running the calculations over and over until they have a really high Effect, so the Engineer could be playing whack-a-mole with the jump drive controls and they still get a net success.

I don't think an Astrogator knows what their Effect is until the jump actually happens. When someone attempts a task roll if a failure isn't obvious then I don't think they know the Effect until they see the results. The rules say he has to roll again if he fails the check, so the Astrogator can tell if he failed, but I don't see anything that indicates he knows what the Effect will be of a successful roll until the Engineer starts the jump.

What is probably routine is taking longer to do the astrogation check to make the difficulty one level lower. So a Jump-2 becomes Simple (2+) Astrogation (1D Hours) with a DM-2 modifier. You have the whole trip out to 100-diameters to do the astrogation calculations, so taking 1D hours instead of 1Dx10 minutes shouldn't usually be much of a problem.
 

ochd

Banded Mongoose
Geir said:
(I actually like 'Astrogation' better but look up 'pendant' in the dictionary and there'll be a link to me...)

Would it be pedantic of me to point out that I think you misspelled pedant? :D :D
 

Geir

Cosmic Mongoose
ochd said:
Geir said:
(I actually like 'Astrogation' better but look up 'pendant' in the dictionary and there'll be a link to me...)

Would it be pedantic of me to point out that I think you misspelled pedant? :D :D

To quote Homer Simpson: "Duh!".
Or is that "Dough!"?
 
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