1. Intercepting a ship that is blockade running.
2. Beating out a pursuer who wants to jump before you do.
3. Attempt surprise by jumping in closer than the Mandeville Pt would normally allow.
4. High Speed Translation (threading the needle)
5. Showing off in front of other navigators

for an interesting dissection of jump points, see The Mote in God's Eye , where

the plot concerns a xeno race where their lone jump point lies within the hot-gas radius

of an exceptionally huge red giant.

For what it's worth, I use fixed jump points. I assign my systems a similar system from Utwig's Traveller Map, since you can enter any date on it and it places the planets in their current locations along their orbits. I use that map only for planetary placement.

Intercepting an inbound blockade runner isn't that difficult. Some Navigator's have a power that helps detect a ship coming in from warp. I think there's a component out there that helps this. You might even allow a Psyniscience check within a certain range. After that, the warp drives are immaterial unless the blockade runner is trying to emergency warp right back out after detecting they were just detected.

If someone is pursuing at a distance then silent running should make the matter moot. If they aren't at a distance then I'd use the pursuit table sidebar.

I can't imagine my players opting for the die roll of instant death over the unknown of silent running. They know I wouldn't fudge on the dice, so forgoing the jump point on purpose is also moot. The show-off Navigator also falls under this heading.

By high speed translation I assume you mean the ship is traveling at such a velocity that they are only within the area of the jump point for a fraction of a second. If using the radii jump point, it's another moot point. Otherwise, a computer probably has to engage the engine at the right time.

With my home-brew Navigation rules the Navigator's skill already affects how far away the translation takes place. Since I use fixed warp points, all your other factors have already been taken into account before the placing of those warp points so I don't ever have to bother with them again. I only permit Navigators with logis-implants to perform that complicated kind of math in their head and still can't imagine them attempting to do so outside their Navigator station anyway.

Red (Type MIa or MIb) super-giants are cool by stellar standards, especially those in their final stages (and perhaps with a planetary nebula forming). They are so cool that there could be planets inside the corona of that star that aren't even liquified, let alone slagged.

In summary, I suppose a party could have all their Navigator bonuses in a row and so ridiculously high that they could reliably make game-breaking jumps possible, so I just worked the whole thing into a Navigation (Stellar) check that determines how many days they translate from their destination. When their destination is unknown I place it somewhere in the Outer Reaches. There is rarely ever a problem with planetary collisions because I assume they all attempt to translate above or below the star's elliptical plane.

this is what I'm talking about Errant.

you do not answer the thread as written.

you breeze right past the actual topic

and insert your own ideas thereon.

I'm not saying your facts are wrong,

I'm saying your ability to join in is faulty.

the key phrase in your reply is this

"I can't imagine...."

You opine at length instead about how

the smart people should run their game,

IE just like yours.

this is why you are are going on block.

Oh my, I hurt his feelings.

If giving examples of how I've dealt with the same situations isn't helpful, that's perfectly understandable. I cannot, however, give examples of something I haven't dealt with before, except in theory. If it's something I've encountered then it seems far more valuable to present a real example than to present theory.

spin it all you like, this is an RPG forum.

its not about hurt feelings, its about signal to noise ratio,

there are 1001 correct ways to do things.

>>>> I cannot, however, give examples of something I haven't dealt with before,

so you could, however, not comment off the topic presented.

and for the record, you did not " give examples of how I've dealt with the same situations"

you changed the wording and therefore the gist of my question.

Please opt out of threads I start, your game style is too dissimilar,

and you wordage is unhelpful, your viewpoint is too "40K" and not enough RPG.

again: I'm not saying your facts are wrong,

I'm saying your ability to join in is faulty.

Let me think about that.

No.

Other people might make comments or suggestions that I care to chime in on. That you don't care to hear me doesn't mean I should remove myself from any conversation you decide to initiate or become part of. If you wish to censor someone, start with yourself.

Conversely, you could just grow up.

Fixed jump points just don't sit well with me, the whole point of the Warp being that its Chaotic (hurr hurr). As for the the points you raised, my input would be to handle it narratively.

As you pointed out, 19 out of 20 times the point will be completely moot, a Stern Chase to the edge of the system usually has ships days away from each other and once one pulls sufficiently ahead to begin warp travel the other has probably given up. For that 1 in 20 time you want it to be more serious, I would just have it be a thing to write up then and there.

But for

The Factors you just listed, those can easily be rendered down to two or three tests to see where the Mandeville currently is in the system, Navigate (Stellar) and (Warp) alongside a Psynicience Test or something similar (i.e. if party has no Navigator or a ship with a heretek device).

• Class / Size of the Ship,
  Should this be a factor? The difference in ship size compared to the vastness of space is pretty insignificant all things considered. I would ignore this to be honest.
  
• Make/ Quality of Warp Drive,
  If you want a rough and ready solution, I would say let the Warp Drive slide as well. By my understanding all it does to begin a Warp Jump is just break open the barrier to the Warp, something relatively "easy" in the context of Warp Travel (seeing as there is no Test for it, I wouldn't bother adding complexity here).
  
  
• Skill of the Navigator,
  Should come into play during the Navigate (Stellar)/(Warp) Tests, don't see much need to go into more detail. Maybe some special bonuses or negatives based on the Navigator's heritage (i.e. maybe a Nomadic House Navigator gets a less difficult test because he's done this more often, etc.)
  
• Size of the Planetary Body,
  Should only really apply if something like a Gas Giant is present, and a **** big one at that or one with an intense gravity field. In either case, that would be represented in the Tests as additional modifiers (the Navigator or relevant character needing to make more calculations to take it into account). For another rough solution, I would use the modifiers from Stars of Inequity concerning Gas Giant gravity an Orbital Feature generation as the additional negative modifier on any Test to quickly ascertain the Point.
  
• Size of the Stellar Body,
  An important factor to be sure, but also something that should be easy to work around for any Navigator. I assume calculating safe distance from any star is the first thing a Navigator in training would be taught, and as such could just be ignored in game. The time when I would have this be a factor to consider is if there is a Stellar Anomaly in play, in which case it should really be something unique and interesting for the players. Special effects and unforeseen difficulties are always fun to put in as a GM.
  
• Warp Flow
  Yeah, you got me there... I gave up trying to create any sort of system for the ebb and flow of the Warp. In my games at least, I try and keep it simple for myself and mysterious to the players. Example for potential modifiers could be roll a 1d5x5 and apply the number as is. Or something like that... KAOZ IZ STRONK
  
• Good navigators can do the math for all that in his/her head !
  On this I actually disagree with you, in fact I actually push in my games that Navigators need to spend hours poring over parchments and running esoteric calculations in their chambers before any sort of Warp Travel can be undertaken. I don't just mean the Divining the Auguries Test, which takes hours in and of itself, but the preparation for a Warp Jump proper. This is just my take on it because I see Navigators as these strange, mysterious beings dealing with forces beyond the understanding of normal men, and the Lovecraft fan in me just loves the idea of long, bizarre computations involving imaginary numbers and chaotic variables. (Says me, who sucks at math )

I can see some value to stable warp points, sort of like Babylon 5 used to use. Various warp storms remain constant (the Eye of Terror, Void Dancer's Roil, some others), and if the warp, even being chaos, as it is, didn't have some consistency/stability, warp charts would be WORTHLESS; the eddies, flows, and 'landmarks' would shift every time, and you'd have no hope, much like how revolutions, drift, and such might make some stellar charts quickly worthless. Having said that, I sort of like "you can punch into the warp anywhere" more, within reason (you need to be outside gravity wells, etc.)

For my part, I usually post here hoping everyone will chime in something. I know that there are people here who don't see things the way I do, or always like what I say, and I've read my own posts; some of them even make me question my sanity, or intellect, so no one's going to really hurt my feelings (to the best of my knowledge, I don't know any of you beyond our chummy chats here, and assume I don't even live in the same area as anyone, either), but even the people who I can envision (I'm arrogant that way, occasionally) saying "oh crap, he posted something, again", whatever they might say might give me some inspiration, or bring to my attention a point I might've missed, or erred. Hell, I might be totally right, and they blazingly wrong, but if it shows me how some other people think, or what they believe, when they formulate ideas, or make assumptions, I can often then come to an easier time discussing it. Take Space Marines. I thought of them as vanishingly rare, compared to most types of troops you might get, but was reminded that Rogue Traders are even more so, thus the Astartes help is not so far-fetched, in their case, or at least not to some. Oh well, this be the Internet, and as soon as two people begin talking, it's likely on account of disagreeing, so... Here's hoping, at least, we'll all stay civil. I cannot remember the author's name, and he doesn't post here under it, anymore, as far as I know (posted on DW threads, if I recall), but I used to just skip his entire posts, like he obliged me with SPOILER tags, and go back to them, if someone else commented in a way that made it seem relevant. Some here might just need to do the same. Babbling complete. Please have a great day, everyone.

I'd suppose the size/class of ship is important to acceleration/speed, which determines time to a warp point.

There are already warp drives that affect travel times in the warp. If you want them to further affect when and where a jump can be initiated, that's an individual choice, though it would be an unnecessary complication for me.

For me, any time PC skill can come into play is probably good. I like to minimize dice rolls, but outcomes affected by character skill is at the heart and essence of RPGs.

Not so much size, but magnetic field and gravity generated by a planet or a star should probably affect jump points. In most cases, the stellar body(ies) in the system have a far greater influence than any planets, thus I tend to ignore the planets.

And yes, fixed jump points or jump points in flux, actual points, or wedges, or radii, or what you, is also personal choice, but one with implications that you might not consider beforehand. I use fixed one because I don't want to keep track of moving ones. Keeping track of moving planets is difficult enough. I like points because it places a military objective in the system...or 2 or 3 or however many. Placing them anywhere a person wants to go opens up a can of worms when trying to adjudicate a war scenario. I refer you to the Atomic Rockets website for a more in-depth assessment of this type of jump point, though here is an excerpt...

The Alderson Drive or "jump point" drive has been used in many SF starship combat games, for the same reason Niven and Pournelle used it: unlike most other FTL, it allows the possibility of interstellar battles. Most other FTL is a "fly anywhere" kind of propulsion, which generally does not allow battles to occur except by mutual consent. Often a planet cannot even detect an enemy invasion fleet until it suddenly pops out of hyperspace. Interstellar wars only last long enough for your hyperspace bombers to fly to the enemy's planets, then a brief emergence to spit out a hellburner, a planet-wrecker nuclear bomb, a planet-sterilizing torch warhead, a planet-cracker antimatter warhead, or a planet-buster neutronium-antimatter warhead. Then they fly home, only to discover that the enemy's bombers were on a similar mission. Go to The Tough Guide to the Known Galaxy and read the entry "SLAG"

If you want more on the subject, try this website.

http://www.projectrho.com/public_html/rocket/fasterlight.php

According to SoI at least, the size of the ship and its speed value is not factored into interstellar speeds. Now an argument can be made to reduce speed by small amounts, especially with very large differences in speed (Mass Conveyor vs Star Clipper) but even so that is a discussion for another board.

As for fixed vs variable jump points, from my experience 40k really has the whole "never commit to combat unless forced" mentality, even described as such in BK. By 40k lore a planetary invasion is supposed to be held back by PDF for months or years until reinforcements arrive.

Honestly I'm not even sure the Imperium can blockade systems, at least not in the way that it would contest jump points.

The invasion of Tyran is a good example, where the Imperial picket ships are docked around the planet and then sent out to intercept the nids (and all die but meh).

Also in the fluff of Port Wander its stated that the edge of the Rubycon system is this lawless place with pirate activity and smuggling galore. The navy doesn't even bother intercepting this since they can just warp or fly away by the time the cruisers get there.

On a side note, where does the term Mandeville Points actually come from? Just curious, I know they are real but I can't remember where I saw them.

the novels mention jump points, and the blockading and reinforcing of them.

BFG does not I think.

That the Imperial Navy doesn't patrol the Outer Reaches of Port Wander doesn't necessarily preclude jump points. It could as easily mean that Port Wander has many jump points, each going to a different system. And if pirates are common there, it would take a capital ship or multiple escorts to patrol each one, or at least each small grouping of them. Rubicon does sound like a MI or MII star.

Hey you'll find evidence pointing to your views where I'll find evidence for mine. Its all subjective in the end since the lore does not state the existence of fixed or variable jump points.

and murphy's law states that when this situation now comes up in the campaign,

it doesn't matter much because the enemy in question is Tau, who don't give a **** about

imperial warp jump methods.

With my GM hat on I like the idea of jump points because it gives a rationale for traps/minefields/ambushes etc.

Without them imagine a circle all the way around our solar system from a point way out past the last planet - that's an enormous chunk of space that could potentially be jumped into making any kind of blockade unfeasible and the chances of randomly emerging anywhere near another ship extremely unlikely (like winning the lottery type unlikely).

Still the warp isn't completely random - the fact that you can have warp routes indicates that there are at least semi stable currents so ships using the same warp route probably should end up in the same general area nine times out of ten.

Different routes to the same sector may have different or the same exit points - any local warp storm or disturbance and all bets are off though - maybe ships are scattered randomly (even dangerously) across the system or maybe it just shifts the exit point somewhere else in the system in a new stable configuration.

As I said - as a GM exiting in the same general area makes for more plot ideas personally - in reality space is huge and ships would barely ever meet but how much fun is that?

I'd say that the 'jump points' are locations where the transition is easier/quicker/safer/etc - but if you really want/need to push things, you can make the jump elsewhere, as long as you're far enough out from the major gravity wells.

Actually, it's probably more accurate to call them "jump zones". I would expect that there'd be a maximum safe gravity gradient on warp translation - or, rather, the warp drive and gellar field can manage only so much gravitational force without problems, and so while it might be technically doable, it would vastly increase the risks and uncertainties involved. How much they can handle would depend on the quality of the drive and field - and a good navigator can probably improve how much can be safely transitioned with, but most ships (especially Charters) would rely on the jump zones, and and they would likely jump only once they were relatively deep into the jump zone they could use, rather than jumping as soon as technically possible.

On a side note, where does the term Mandeville Points actually come from? Just curious, I know they are real but I can't remember where I saw them.

various places click here

also these: lexicanum

While I don't see Babylon 5 jump gates in 40k, I like to presume that, if the warp is a soup of death, there are a few places where the crackers, the vegetables, and what have you are thinner, or less prevalent, and these would make the best locales for your spoon (read: ship) to enter. If Rogue Trader can try to tell me that "warp route charts" are a thing, and even a somewhat reliable thing, when we are talking about an ever flowing, ever changing medium, riddled with destructive storms, eddies, calms, and is the plaything of Tzeentch, and that most people cannot even see, there must be some places where it easier to enter, and where you can expect incoming people to exit. Also, if the chart is ever to be any good, at least some of theese conditions need to remain at least somewhat consistent (no "wandering wormhole entrances", as in Star Trek). As was said, otherwise it would be very difficult to be a pirate, and hope to ever catch anything. As was said, if you have to risk it, and force yourself past the crackers, and dumplings, you can, but that makes for harder eating of your soup...um, that makes for harder warp travel.

Indeed. I'd see it as a mix of both things; if you go far enough away from the star, you'd be able to jump anywhere, but there will also be safe 'zones' or 'points' deeper into a system; it's often implied that Gravity is an issue so Trojan points between a gas giant and the star (or between a planet and its moon if you're really good or slightly suicidal) are also potentials.