Velocity and Jump Space

Nerhesi

Cosmic Mongoose
Maybe this is being a little over the top.. can we put the rest the whole crazy Velocity is maintained after coming out of jump-space thing?

If we say you come out with Velocity 0, it completely removes that problem of Jumping in system and releasing massive amount of kinetic vehicles to obliterate a planet before it even realises there is a threat...

Thoughts
 
Ouch, yeah, I second this.

Too easy to wipe out a planet like that.

:twisted:
But if you did, even in a system outside of the Imperium, I have a funny feeling that they would stop at absolutely nothing to hunt down and terminate the offenders, their families, friends, pets and even people who may owe them money. :twisted: :shock:
 
Yeah I've always declared turn n burn on the way out and the way in. Hand waving and saying the 'relative stop' in the departure system was a similar 'relative stop' in the arrival system. When the PCs were in trouble though... Of course they want to burn all the way to 100 diameters. I tried to impose negative DMs on arrival but it was always a kludgy bolt-on.

I agree - jettison maintained velocity. I say impose a turn n burn each way.
 
The disadvantages are what might be encountered when you exit jumpspace especially as long as there is ANY chance for a minor misjump. There's nothing saying relative exit velocity is physically impossible in Traveller. Player should have the option as to how they enter and exit jumpspace and possible consequences, if any, are the realm of the ref. Much more exciting than it always goes perfectly. Velocity and distances at exit are also important for the first sensor sweep.

Not as a rule on paper but players should state at entry time what their velocity is going in so the ref can have a reference for what may occur at exit. Remember, it could be just as bad being a full relative stop in the new system.
 
The problem is allowing any exit velocity, opens up the military applications of this tactic, drastically changing strategic combat.

making the roll at an 8+, results in ending up exactly where you want. Easily plottable info to annihilate any highport, planetary depot, city - especially when the stuff jumping in is at some near-c velocity.. if you're lucky, you may get 2-3 seconds to detect something with passive sensors appearing at the 100D range
 
The only thing canon on this was written by Miller way back when. In it he had the rules where ships retained speed and heading. I've never seen it written anywhere else, and it was never incorporated into the rule sets.

I think the easiest way to handle this is to say a ship that enters jump space with any velocity retains it upon exit, but that there exit vector is random. Which would imply that you could jump while under full speed, but you might be spending hours slowing down to a relative stop to get back towards where you are going. So it allows for it, but also penalizes it. So most ships that aren't fighting will come to a stop before jumping.
 
phavoc said:
The only thing canon on this was written by Miller way back when. In it he had the rules where ships retained speed and heading. I've never seen it written anywhere else, and it was never incorporated into the rule sets.

I think the easiest way to handle this is to say a ship that enters jump space with any velocity retains it upon exit, but that there exit vector is random. Which would imply that you could jump while under full speed, but you might be spending hours slowing down to a relative stop to get back towards where you are going. So it allows for it, but also penalizes it. So most ships that aren't fighting will come to a stop before jumping.

That would work too - perhaps it should be indicated as such. I only raised the point because on an 8+ jump, you ended up exactly where you wanted, which to me would denote facing maybe too :)

But yeah Phavoc - good call. Random vector makes it useless as a military application
 
For a fleet to come screaming into a system with every ship making their jump check so they're in formation sounds like a Pearl Harbor situation and all those in-system defense stations and fighting ships assume there couldn't possibly be a threat to security and the military grade sensors with upgrading aren't being fully manned or the weapons attended. You really think a military force would not conceive of such a lightning strike? Obviously the attackers do.

Coming in full throttle with little to no sensor intelligence of the surroundings should be a disadvantage. You're in less control especially within the 100D range. You might have a good clue where your ship will exit but you have no idea what is there at exit and high velocity very well could mean you can't react to hazards.

This is why written Traveller naval SOP has fleets away from the target to start in positions to react to the unexpected, gather immediate intel, organize then begin an operation.

Best guess for the High V attack is a suicide run. At the least expensive is a 100 tonner stripped of all but fuel for jump and the least needed for endurance to a target, the bare minimum for a cramped bridge and maybe no stateroom then pack the ship with explosives. Target a system taking all the time you need for the most accurate jump and accelerate to maximum as you enter jumpspace then wait to reenter. Make any small corrections to deviations at exit and remind yourself it's a worthy sacrifice.

Except you never hear about such incidences which says defenses are actually prepared for it. If these scenarios were all that easy for all these hundreds of years in space, they would occur regularly. Obviously they fail more often than not and tacticians go back to plan A.
 
An 8+ jump puts you exactly where you want to be.Perfect entry with exact velocity and calculations that can be done weeks before due to well known orbits and fixed locations of bases. You don't need to worry about calculation, sensors or anything. You jump in blind, and if you make your (usually) trivial jump roll, you are guaranteed to obliterate a city/base/orbital platform/planet/etc...

...

Well - at least I thought so until I realised we both missed something Reynard. At least in MGT, when you jump in, you arrive after [148 + 6D hours]

So.. this is a non-issue, probably due to a completely indirect reason that I guess did exist before in other versions of Traveler? I hope? The fact that it takes less than an exact amount of time to jump, means you can't have anything pre-calculated prior to the jump.

This is a good thing :)
 
The time factor has been part of Traveller for a long time. That's why it's been stated fleets jump into a system at safe distances to wait for all the ships, or at least a significant majority, to reenter.
Yeah. 6 to 36 hours variation can be a pain when you're on a tight military schedule.
 
Having jump "magically" put you at zero velocity relative to your destination would be my choice for simplicity's sake.

If velocity is retained, there's no reason that you should be traveling the same velocity relative to your destination that you were relative to your starting point, due to the fact that the two planets are likely moving at different speeds and directions.
 
Yes, the randomness for emergence has always been there. And fleet jumps have never been directly addressed except in some supplememts. The last MGT supplement was taken from the D20 rules and more or less brought over intact. In there it talks about synching jumps between ships to get more ships to emerge as a fleet. It certainly my deserves a paragraph or three, since fleets and squadrons are multiples. And not to mention players will sometimes have multi ship units as well as escort missions, or they are being escorted.

I think it would be easy enough to fix if only the powers that be put some effort into addressing it finally. A paragraph belongs in the CRB and expanded section for fleets belongs in HG.
 
"If velocity is retained, there's no reason that you should be traveling the same velocity relative to your destination that you were relative to your starting point, due to the fact that the two planets are likely moving at different speeds and directions."

This has been brought up many times before. Those honking big ship computers some people whine about being too big are made to store an enormous amount of known system data and then process that data, including the relative vector information for a target location for the time emergence is expected. Pat your astrogator and the computer for jobs well done! That's why scout vessels enter new systems above the system plane at the distance of the Oort region (50k AU). That's also why jumps aren't absolutely precise. When you exit jumpspace, you have a fairly good idea where you will hit and adjust your ship's vector and desired velocity relative to the target system for any minor (or major) corrections. Since it's no an exact science, most starship crews will take precautions in the event they don't hit the bullseye, they go slower before arriving then look around on entry and adjust vector and velocity to complete their objective.

Everyone, don't get so hung up on this. The inexact nature of jump should be part of the fun and excitement and definitely part of the ref's bag of tricks. So far I, as both ref and player, have enjoyed the thrill of what awaits at the other end of a jump. Unless you have a ref who's tiring of running a Traveller story and wants to TPK the group it's part of the thrill ride.
 
Reynard said:
"If velocity is retained, there's no reason that you should be traveling the same velocity relative to your destination that you were relative to your starting point, due to the fact that the two planets are likely moving at different speeds and directions."

Angular momentum of two opposing star systems is mentioned in the original writeup of jump space and retaining your speed and course upon exiting. You might be able to make use of it or not, but the article never went into any sort of details about how to model or roll for errors.

Reynard said:
That's why scout vessels enter new systems above the system plane at the distance of the Oort region (50k AU). That's also why jumps aren't absolutely precise. When you exit jumpspace, you have a fairly good idea where you will hit and adjust your ship's vector and desired velocity relative to the target system for any minor (or major) corrections. Since it's no an exact science, most starship crews will take precautions in the event they don't hit the bullseye, they go slower before arriving then look around on entry and adjust vector and velocity to complete their objective.

That's only the initial jump, and it's done for a number of reasons. First is to map out the system from a much closer range. You'll get more detail you would not from light years away. But it's also done to determine if there is any industrialized worlds or advanced species. Once those two activities are done, the scout would jump closer to begin the system survey.

Jumps are, in some ways, pretty precise if you look at the distance you travelled.

Reynard said:
Everyone, don't get so hung up on this. The inexact nature of jump should be part of the fun and excitement and definitely part of the ref's bag of tricks. So far I, as both ref and player, have enjoyed the thrill of what awaits at the other end of a jump. Unless you have a ref who's tiring of running a Traveller story and wants to TPK the group it's part of the thrill ride.

The point of the discussion has always been one of better understanding. When the rules are clear you can take your fun and excitement in new directions rather than hitting that fracking wall of "uh, wait, you can't do that" "uh, yes I can. Rules don't say I can't" "uh, rules don't say you can" Cue the discussion for 30min on what should or shouldn't happen.

All of the fun times can STILL happen with a good ruleset that defines the boundaries of the gaming system. Just fewer argument ensue. And that's a GOOD thing! :)
 
" You might be able to make use of it or not, but the article never went into any sort of details about how to model or roll for errors."

Not every article must super detail a game phenomenon or spell out every die roll. The general description is enough to make its point and give enough clues for referees to create a situation and any, if any, die rolls. Thing is, it's been part of Traveller for a long time.

"That's only the initial jump, and it's done for a number of reasons. First is to map out the system from a much closer range. You'll get more detail you would not from light years away. But it's also done to determine if there is any industrialized worlds or advanced species. Once those two activities are done, the scout would jump closer to begin the system survey."

I'm using information from Book3: Scouts. According to it, you jump that far away because "...this allows maximum chance of *avoiding uncharted bodies*, minimal interference in system scanning and maximum discretion if the system is inhabited." A jump is fairly accurate but with little to no knowledge about a system, you don't jump in to it blindly. It's the scout service in the beginning that map data for all other vessels to use a system while ships in general help update a system as their sensors sweep within. That's why ships in known systems have little to fear NORMALLY when they calculate a jump into known systems.

Read Scouts, has all the info about system survey.

Again about the precision of jumping and why you don't exit in the center of a target location, this is from Sector Fleet: "There is still variation in emergence, however. Using a linked Jump reduces variation in time to about an hour either way in most cases. Position variance is minimal. This means that fleets can Jump en masse and be ready for combat at the far end, but a fleet emergence is still an exciting time for all concerned, as vessels emerge in the wrong order, on slightly different vectors, and dispersed in time by up to 2 hours. The variance is greater for large fleets. A single vessel and her escorts are likely to emerge all together. Larger forces are not."

Yes , even with squadron jump engines, it's a bad idea to think you can attack a target with a full fleet at the moment of exit. The first ships to emerge would alert the enemy who would have initial superiority of firepower then would wait for each group of ships to follow. Reminds me of the end battle in the Wing Commander movie.

There is no problem with velocity and jumping in Traveller. It has been established for decades and game mechanics and gameplay has developed around it as seen above.
 
It's a judgement call by the commanding Admiral, and dependent on his confidence in his hardware and the Master Chief Fleet Astrogator.
 
Reynard said:
Those honking big ship computers some people whine about being too big are made to store an enormous amount of known system data and then process that data, including the relative vector information for a target location for the time emergence is expected. Pat your astrogator and the computer for jobs well done!

But if the velocity is retained, why in the world would you need to slow to a relative stop before you jump out? This is how it is in the the current CRB.

Also, if the velocity is retained with the precision you're talking about, how easy is it to throw a ship traveling at a significant percentage of light speed at an inhabited planet? I think this is the problem that was originally brought up in this thread and why the suggestion for jump not retaining momentum was made.
 
Reynard said:
Not every article must super detail a game phenomenon or spell out every die roll. The general description is enough to make its point and give enough clues for referees to create a situation and any, if any, die rolls. Thing is, it's been part of Traveller for a long time.

That's true, and I don't expect that. But some things do indeed require clarification. Using your example above the rules could state "Lasers cause damage via energy at a distance". But how much damage? At what distance? The whole point of having a rule set is defining things in non-ambiguous terms. IF it's simply meant to be informtional reference and isn't key to game play, then I agree with your position. I think the debate here is more centered along the lines of whether or not being able to retain your vector and speed upon exit from jumpspace in your arrival system is possible, or not. This actually can radically effect encounters as well as PC actions. If you've been boosting the entire time to the 100D limit you have a lot of G-turns behind you. Being able to bring those into your arriving system can drastically effect your travel times.

The other issue here is that this was written as a JTAS article, as many new rules and interpretations were from CT. It's been relatively ignored since then in the various versions, and it's also been raised as a question in the various versions since then. Because a rule re-write is underway it does make sense to have the discussion now and try to resolve it one way or another. Personally I'm in favor of reducing ambiguity whenever and whereever possible.

Reynard said:
I'm using information from Book3: Scouts. According to it, you jump that far away because "...this allows maximum chance of *avoiding uncharted bodies*, minimal interference in system scanning and maximum discretion if the system is inhabited." A jump is fairly accurate but with little to no knowledge about a system, you don't jump in to it blindly. It's the scout service in the beginning that map data for all other vessels to use a system while ships in general help update a system as their sensors sweep within. That's why ships in known systems have little to fear NORMALLY when they calculate a jump into known systems.

Read Scouts, has all the info about system survey.

I did find the section in question:
Entry into a new system is typically made at much greater distance than a typical system jump. The default entry point is above the system’s orbital plane (ecliptic) in the Oort region (typically 50,000 AU from the star); this allows maximum chance of avoiding uncharted bodies, minimal interference in system scanning, and maximum discretion if system is inhabited.

Only the MGT Scouts book specifies a 50k AU entry point. It's not in CT, or MT, or TNE (but jump shock is here!). But the rest of the paragraph is the same thing that I mentioned. This is a rather moot point, as the Imperium is explored and stellar cartography data exists on pretty much all of the surrounding space (where else did TravellerMap get it's cartography?). Still, a scout ship could easily come in much closer to get a better read on the system. But yes, being that far out pretty much guarantees you won't be spotted.

Reynard said:
Again about the precision of jumping and why you don't exit in the center of a target location, this is from Sector Fleet: "There is still variation in emergence, however. Using a linked Jump reduces variation in time to about an hour either way in most cases. Position variance is minimal. This means that fleets can Jump en masse and be ready for combat at the far end, but a fleet emergence is still an exciting time for all concerned, as vessels emerge in the wrong order, on slightly different vectors, and dispersed in time by up to 2 hours. The variance is greater for large fleets. A single vessel and her escorts are likely to emerge all together. Larger forces are not."

Right. But Sector Fleet ISNT't MGT canon. If you read it closely you'll see that it was never updated to bring it in line with MGT universe - for example jump grids are still in there. That section you are referencing also talks about all naval ships being equipped with Squadron Jump systems. Nowhere else, book wise, is this system referenced. There's no civilian mention of it - Sector Fleet obviously being a purely naval supplement - so one could argue that this, too, is not canon for the MGT universe. But since it got the MGT publishing label slapped on it, by default it becomes canon. So between the lines I treat it as pseudo-canon, or something that has some interesting ideas, but I don't go too far down the rabbit hole because it's easily going to break something else.

Reynard said:
Yes , even with squadron jump engines, it's a bad idea to think you can attack a target with a full fleet at the moment of exit. The first ships to emerge would alert the enemy who would have initial superiority of firepower then would wait for each group of ships to follow. Reminds me of the end battle in the Wing Commander movie.

First... ugh... a reminder of just how terrible Wing Commander the movie was. People were walking out it was so bad. Das Boot in Space!!! :)

The idea of more than two ships jumping in tandem and arriving more or less at the same time is something that really does need to be addressed. We can't use the idea of specialized, and apparently, purely naval jump navigational systems because PC's wouldn't necessarily have them or be able to always travel with one. And really, it comes down to computer processing to determine that. It's fine to keep some of the vagaries of jump space and attach them to multiples of ships. But just how many? Should it be 1hr? 3hrs? Can you do something to reduce it?

Sure, it also makes sense for naval forces to jump and arrive distant to the defenders so the attackers can gather their forces, organize and move out. On the flip side you give defenders time to rally. And wonder if the arrival is a feint or not. I would assume most fleet actions are going to take place near something worth fighting over. Fighting in the middle of nowhere doesn't make much sense if you are a defender since you can utilize any defenses you might have. Maybe if you have to worry about the enemy indiscriminately bombarding your planet from orbit, but that would trigger 3I intervention, and it would seem that none of the sophont races are terribly eager to glass an enemies planet from orbit. So that option is more or less off the table.

Reynard said:
There is no problem with velocity and jumping in Traveller. It has been established for decades and game mechanics and gameplay has developed around it as seen above.

Actually, there is. Because it hasn't been defined in the printed rule sets. The only reference I am aware of is the JTAS article from CT. And as I mentioned up-thread it would be nice to resolve this ambiguity with a few sentences once and for all - or at least for MGT-2. Then once we know the parameters we can play with the rules as we see fit.
 
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