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To vector, or not to vector...

some vector scale sizes by duration of turn... in traveller G's (10m/s/s) / Real G's (~9.8m/s/s)

1 minute: 36km/35.28km
5 minute: 900km/882km
8m 20s (500s): 2500km/2450km
10 min: 3600km/3528km
16m 40s (1000s): 10000km/9800km

Note that on the turn accellerated, you should only cross half the distance, but the mechanics of Bk2, Mayday, and Brilliant Lances ignore that in the interest of playability. I actually use 1min & 18km/hex, start the turn with current and future markers, and move the current 1 per G used, and the next turn 3 per G used. (the one for this turn, and the 2 it will actually move thereafter).
 
I, too, love the vector movement system, especially with hex maps as it's done in Mayday, but in a typical Traveller running battle between two ships, it's largely pointless.

I agree. I've run several combats over the years using the pseudo Mayday-meets-Starter Traveller method (10,000 km hexes), and really, the Starter Traveller Range Band system is all that's important. You just need to know how far it is to the next ship. That's it. Actual vector, or direction from the players' ship, doesn't mean a hill of beans.

You just need range. The GM can fill in the color.





I've said this several times over the years on threads like this: What I do is use Starter Traveller for role playing space battles.

I take the deck plan of the players' ship and I place it on the table in front of us. Then, I play Starter Traveller by the book, with the Range Bands (keeping track of range in my GM's notebook), but I play everything from the player's perspective.

Range in Traveller space combat is so long that the combatants never get to visual range (what...10,000-30,000 km or so?) unless the two ships are docking/boarding. Otherwise, it's just black space out there when viewed out the portholes.

When the players want range, I look down at my Range Band chart and then I describe what they see on their sensors.

We role play the whole situation, playing through the various steps in space combat given in Starter Traveller. The gunner sits at the gunner's station. The action takes place a lot on the bridge. And, if the ship is hit, it's fun to run around with the engineer as he fixes parts of the ship.

This is where the space combat swings into role playing many times. In one of the combat phases, which are 1000 seconds long (just over 15 minutes), I'll describe what the engineer sees when he gets to the damaged area. Or, maybe he has to go EVA outside the ship--that's fun during combat.

The doctor, too, might have his hands full is someone gets hurt.

Sometimes, communications are knocked out, and the gunners can't communicate with the bridge.

Things like that.

All the action is focused on the ship, in front of the characters, through their instruments, even though I use the Starter Traveller/Book 2 space combat phases, keeping track of range with Starter Traveller Range Bands.

For me, this is the only way to go with small-ship combat (and High Guard for larger fleet encounters--I'll do the same thing with HG, keeping the focus on the bridge of the players' flagship and using HG battlelines to keep track of range, describing what the players' see on their scopes. You can have some damn nice Honor Harrington style combats this way, and the characters seem to "mean" a lot more to the scenario even though we're using High Guard rules).
 
Keeping the PC's engaged is essential, and I love S-4's dynamic for small ship encounters. Everyone is literaly 'in the same boat' as it were, and need to feel the potential threat of having to face a long walk home through deep space vaccum.
 
Keeping the PC's engaged is essential, and I love S-4's dynamic for small ship encounters. Everyone is literaly 'in the same boat' as it were, and need to feel the potential threat of having to face a long walk home through deep space vaccum.

That's right. During the Movement phase, I'll ask the pilot how he's controlling the ship (while keeping track of distanct to the enemy using Range Bands). The player may say, "Fredi will slow our velocity by 1G."

So, I'll go into roleplay mode, describing the situation. This from the eyes of the Navigator: "Outside the port you see the stars trace across the blackness. You feel the attitude thrusters burn. On your scope, you can see that the ship has completely flipped its facing so that the aft end of the ship leads the bow in the vector of travel.

"You look over to your left and see Fredi with his hand on the thruster lever. Gently he engages it, and there is a slight jerk as the acceleration compensators adjust to the massive thrusters igniting for a burn that will slow the velocity of the ship."

In the Enemy Laser Fire phase, I may startle everyone: "ENERGY SPIKE!!" But, before the Navigator can spit out the info, the ship is slammed from an exposion.

The player playing the pilot may say, "Damage Report!"

And, I'll respond, for the Navigator, "Fuel tank number seven hit. We're spewing L-hyd all over space."

I usually focus on the engineer and damage control in the Game Turn Interphase, in between space combat rounds. A hit like that above--a Fuel hit on the Hit Location Chart--could probably be taken care of from the engineer's damage control station on the bridge or in engineering. Here, I'd describe how he would use the ship's damage control systems to seal the leak. Standard 10 ton tanks can be sectioned from the main fuel bladder using interior seal points. The engineer's job is to squeeze out more efficiency from the system. The tank will seal after losing 10 tons of fuel (as the damage reads on the book), but I allow the engineer to apply his skill, throwing 2d6 (or 3d6, depending on my mood), modified by engineering skill, to save precious fuel. Let's say the ship's engineer has Engineering-1. I'll let the player throw 2d6 -1, and let the sum be the number of tons lost before the engineer was able to get the seal points closed. If the ship is massively damaged, I'll degrade systems. This same fuel hit may be a 3d6 -1 roll with a max of 10 tons (or not).

The Ordnance Launch phase is always fun because the players don't really know what was launched--missiles or a small craft or what.

"You're picking up two bogeys from the exact point of the enemy vessel. They're picking up velocity and are on a collision course for the ship."

"Range?"

"Just now, 67,250 klicks."

I always make up non-round numbers, too. It adds to the role playing aspect.



The game is run exactly as is presented in Starter Traveller (same phases as Book 2 but uses Range Band movement). I don't change any of that.

It's the way the phase information is presented that's different. I role play it out instead of have players play a war game on a hex board.

I find it much more involving this way.

Space combats are a real hoot. And, the captain always seems to wince with every piece of his ship that is carved out.

Players tend to remember the space combat encounters as lively exercises, too. It's akin to actual adventuring.
 
Oh I emphasize the role-playing aspect as well, the map used - be it butcher paper plotting or hexes - is there to represent what the players see on their screens during the action. It doesn't detract from the storytelling aspect so much as emphasizes it by giving them a visual reference and help with their tactical choices.

The expanded hit location tables help with detailing what pieces get carved out of the ship and helps the crew prioritize emergency repairs, just like having their deckplan out on the table in a plastic cover I draw on with grease pencil to show the damaged sections, what's indicated as being in vacuum now, etc..

I can make it all work without any of the above if necessary, and have, I just would prefer the whole nine yards because in the past it has always added a lot to the game. It makes a huge difference letting the players plot their courses and try to intercept or run from other ships while using vector movement.

But for combat, and all interactions, I always emphasize the role-play. S4's example sounds a lot like what happens in my combat sessions, with the exception being that I'll hand notes to players so they can yell, "They are firing!" Then I'll tell them that beam lasers just lanced through the cargo deck, warping/jamming the ramp and slagging the ATV, and 2 missiles on an intercept are announced by the collision klaxon going off.

Players isolated in different parts of the ship that get cut off comms for some reason or another have to blue-book what they do with me until the engineer gets comms up again, and those in the sections hit have to make saving rolls to avoid the 250MW lasers blasting through the bridge, or whatever. Oh, it can get deliciously ugly when a section is closed off by the ship's damage control systems and someone in there is in a holed vacc suit or wounded.

But see, with all that going on it just adds to the whole experience to be able to include the "wargame" parts to help flesh it out. Especially since once combat of any kind starts in my games I don't allow for a pause button for the party to talk it over, in or out of character, unless it's a natural condition for the moment. The stress goes up that way and more drama results.
 

There's an interesting discussion at that page about space games that's specifically pertinent to this one.

Basically, the simple point that in a space game with no terrain and no facing limits, maneuver is basically pointless.

Maneuver is based upon getting an advantage on the opponent. Whether that's leveraging cover, "flanking" them, whatever.

In traveller, especially book 2, there is no maneuver. Well, there is, but in the end, all it really affects is range. That's why the range band versions work so well.
 
Range band tends to cause players to more readily overlook the imperatives of real vector-based space travel:

1) courses are optimized for either time or fuel
2) combat maneuver* ensures being off course for both time and fuel economy
3) bringing weapons to bear will often involve coming off-axis.**
4) Mid-cource speeds are relatively high in time-priority courses.

* for continuous burn courses, this includes changing to just coasting.
** Ignored in many editions of Traveller.

Further it tends to cause people to ignore that, once you get 3 bodies, you have defined a plane, and at 4, more often than not, one crosses into 3-D.

The 3-D to 2-D collapse loses little in comparison to the gain in playability, but the 2-D to 1-D

Imperative 1 drives imperatives 2 & 4...

In a fuel efficient course (incuding Hohman transfer orbits) even being hit may result in missing the target planet, especially if one has JUST enough fuel for the course as plotted.

In a time efficient course, one where either one has sufficient fuel for burn whole course, or an intercept during decelleration phase, each second delayed can be kilometers (or for longer courses, thousands of kilometers) by which one misses the target point... either by arriving too late or too early for intercept, or by overshooting the target point, or even smashing into atmosphere and/or rock. The speeds are impressive (1000km/s is 4.7 hours at 6G...).

Even engineering the intercept is tricky.
 
There's an interesting discussion at that page about space games that's specifically pertinent to this one.

Basically, the simple point that in a space game with no terrain and no facing limits, maneuver is basically pointless.

Maneuver is based upon getting an advantage on the opponent. Whether that's leveraging cover, "flanking" them, whatever.

In traveller, especially book 2, there is no maneuver. Well, there is, but in the end, all it really affects is range. That's why the range band versions work so well.

This is why I used Mayday for vector movement: missiles had limited numbers of burns and therefor vector changes. So a ship could out-manuever and/or outrun a missile if they played it right. Same with things like fixed forward weapons like on small craft and Solomani-built ships; they require facing, and facing can be figured into Mayday as a maneuvering limiter.

Plus the direction of sand cannisters fired, hazards to navigation (which might be a part of your ship or cargo that fell out and is now moving along the last vector), and little things that keep every combat from turning into a generic numbers game.

At least on the player level. HG is different.
 
Range band tends to cause players to more readily overlook the imperatives of real vector-based space travel:

If you're comparing to Book 2 vector based movement, then I totally disagree.

1) courses are optimized for either time or fuel

Time, maybe. But, fuel? Not really. Most ships carry, what? Two weeks worth? Combat burn isn't going to change that. Not with Book 2 combat.

2) combat maneuver* ensures being off course for both time and fuel economy

No biggie. See above.

3) bringing weapons to bear will often involve coming off-axis.**

As your note says. This is ignored in Book 2 combat. We're talking about 1000 second turns with small ships. There's plenty of time and movement to bring all weapons to bear.

Even with High Guard, all but the largest ships can usually bring all batteries to bear.

) Mid-cource speeds are relatively high in time-priority courses.

So, you've basically hit upon time as an issue. Sure, combat may throw you off course....but, unless it happens at either the launching point or the arrival point, combat probably isn't going to change your course much--not unless you've ignored the vector of the entire trip.

Why?


Let's say you leave one planet heading for another, and it takes 2 days to get there. Three fourths the way into the trip, you get attacked by pirates.

Your vector isn't going to change much because you've got a very, very long vector. You've just accelerated for an entire day, and you've only accelerated for half the time it takes to slow the ship down. You may be able to change vector by a degree or two, but this will still take a lot of time.

A lot depends on your M-Drive and the enemy's M-Drive.

So, space combat that happens in-between journey points is like two dragsters on a strip going broadsides with each other. They can't change the direction of travel within the period of the fight. They're just two vessels, both going very, very fast, trading blows.

This is why the Range Band system works so well. Traveller space combat isn't like Star Wars with ships darting and banking all over the place. Many Traveller space combats have ships going in one direction only.

Movement is more interesting in a ship's relative speed is slow, at the launching point or at the landing point.

Otherwise, it's like two missiles, moving in a straight line, firing their weapons at each other across the distance between them.

In the case of the ship in the example above, it will still take another 12 hours before the ship's M-Drive can alter velocity enough to make significant course changes.



This also has neat implications on role playing. You may be very close to a ship in distress, being attacked by a pirate. But you and your vessel can do very little about the situation but sit back and watch your monitors if the velocity between you and the combat ships is great. If you're moving significantly slower, the two fighting vessels will zoom past you like you're on standing on the freeway watching cars zoom by.

If, otoh, you're moving much faster than the combat ships, the opposite is true. You're the one in the car on the free way, doing 80 mph, and see two people fist fighting on the sidewalk. There's little you can do but zoom past and watch. If you're lucky, you can get one shot in while you pass, but that's it.
 
That "Degree or two" is several dozen thousand km, S4.

And not everyone uses CT PowerPlantOn==ThrustOn. In fact, MGT, MT, TNE, and T4 all have fuel using drives available... in which cases, fuel conserving routes are common.

And an intercept 3/4 of the way in? Not bloody likely to be effective... the vectors wont match or the pirate will have been burning brightly for long enough that EVERYONE else knows what is up, and the merchant can then burn to add vector...

I've played this out in mayday dozens of times. It's F*ING hard for a pirate to intercept you mid-burn. Either wait at the jump-in and grab them in the first part fo the burn, or take them at the end... but your proposed 3/4 of the burn is just about the STUPIDEST place for a pirate to do so... it's obvious he's burning for intercept. Even if he succeeds, he's also got no chance for a safe exit.
 
& if you do manage to match vectors & speed mid-journey, then its only velocity relative to each other that matters, not the planets of origin/destination.

Relative velocity is dependent on your choice of the point you choose to be most relevant. The choice of origin or destination will produce significantly differant relative velocities, as will choosing the local star or a star 3 parsecs away, as will choosing the pirate thats behind you & catching up...
 
And if you have fuel, time, or delta-V limits, your ability to vary your own is constrained.

The actual mid-course velocities of ships heading for even a size 1 world are high... from 100,000km inbound, peak velocity under 1G is 31.5km/sec; at s4's proposed 3/4 intercept (by time*) you're still doing 15.25km/sec; each of the 360 seconds in a MGT ship turn (the shortest canonical turn in Traveller rules) you are not decellerating is another 11,340 km by which you'll miss your parking orbit. Plus the off-axis diversion of uncancelled thrust needing to be canceled taking even MORE time. And, due to Newton's Laws of Motion, even in a lovely situation of unlimited delta-V, you still have missed your stop, and have to then boost back in. You simply can not make up for thrust loss on the braking leg. Also note: larger worlds, considerably higher vectors. Each turn mid-course you lose is 5-10 turns lost coming back to course

Now, there is one case where such an intercept works; discovered by a player of mine in the 80's. A real surprise to me at the time... knowing that the intercept in midcourse meant only one shot en passant, he shot for power plant. He hit, and killed the plant. He then proceeded out, knowing he'd just made the "enemy" freighter not only pay ludicrous repairs, he'd done so by making them bloody hard to catch up to... and repairs of drives take hours... hours of flying at high rates of speed.

*using time because it's easier to calulate.
 
That "Degree or two" is several dozen thousand km, S4.

Over time. The ship has plenty of fuel to compensate. It's not an issue.

And not everyone uses CT PowerPlantOn==ThrustOn. In fact, MGT, MT, TNE, and T4 all have fuel using drives available... in which cases, fuel conserving routes are common.

The game is different depending on which version is being used. I specifically directed my comments at CT. T4's Brilliant Lances is a whole other animal, for instance.

And an intercept 3/4 of the way in? Not bloody likely to be effective...

Which is why I said most attacks happen at launch or landing point.

the vectors wont match or the pirate will have been burning brightly for long enough that EVERYONE else knows what is up,

Yep. Victims will know for a long time--maybe mucho hours--that they will be attacked.

The thing is, typically, there ain't much that can be done about it.

If a Free Trader is 3/4 the way through its 2 day journey, it will know that a suspicious ship approaches and is matching vectors. They'll know hours before that its a possible pirate attack. And, they can communicate this to the starport.

But, unless there's some help very close to the Free Trader, that must also be close to matching vectors with the Free Trader, there ain't much "help" can do about the attack except to sit back and watch.

It's hard to hide in space. Pirates are more likely to look like freighters than they are to hide close to space debris. Unless escorted by a policing vessel, most ships in the system are game for pirates.

Why?

Pirates will calculate vectors of all other ships with regard to their prey. They'll estimate getting in, matching vectors, overcoming the vessel, transferring cargo, and jumping out, before "help" arrives.

Many times they can do this with the starport and the rest of the vessels in the system watching, helpless, because no ship is close enough to match vectors and help out.

I would guess that protocol in piracy-risky systems is large convoys of vessels, when possible, taking the same route.


I've played this out in mayday dozens of times. It's F*ING hard for a pirate to intercept you mid-burn.

Absolutely it is. A pirate can't just wait out there and hope to get up to speed in time to intercept.

It's best if pirates jump their prey with lower M-Drive ratings. A pirate M-3 to a prey using M-1 is a great advantage.

Still, the pirate vessel has to spend time matching vectors, and as its doing this (which can take hours), the mouse is tipped off that the cat is after it.

The key to piracy is not Surprise attack with Traveller (CT) space combat. The key is finding prey that has no hope of getting help for a specified time. As I said, most pirate attacks happen with the entire star system watching.

This is probably how some pirates get famous, even if they leave not witnesses on the prey vessel.

Either wait at the jump-in and grab them in the first part fo the burn, or take them at the end...

Yeah...I said that.


but your proposed 3/4 of the burn is just about the STUPIDEST place for a pirate to do so...

Hardest, not stupidest. It's more like hardest and smartest.

Mid burn is where the ship is helpless. It can't maneuver. It can only travel in a straight line. And, help is not likely to be around to mess with the pirate.

Again, a superior M-Drive is necessary for the pirate.

And, remember, the launch or landing points are easier pirate targets, but that's also where the help usually is.



it's obvious he's burning for intercept.

If no one can do anything about it, it doesn't matter.



Even if he succeeds, he's also got no chance for a safe exit.

How do you figure? He matches vectors. He overcomes the prey. He transfers cargo. He jumps outsystem.

Exit complete.
 
If he jumps an inbound, he's within 10 diameters at end, or really close to it; nearly automatic misjump if he jumps out, and guaranteed intercept by local forces if he doesn't.
 
Gents,

First things first. S4, you really need to play out a couple interception attempts in Mayday and/or LBB:2. Really as in really, really, really, really, need to.

Just last week Matt123 posed an interception question in a thread with regards to commerce raiding in which the raider a three times the acceleration of the merchant, started on the 100D limit sphere only ~85 light-seconds away, and still couldn't match vectors until the merchant had reached the gas giant's cloud tops. And all of that assumed an instantaneous start which required detection ranges which far exceed all but one of Traveller's space combat systems.

On to the topic...

As all of you are undoubtedly sick of reading me post, my groups were wargamers first and roleplayers second. That meant pulling out a hex map for Mayday or setting up counters for LBB:2 was a common occurrence in my games. Space combat may not have been common, but moving ships along vectors via Mayday and/or LBB:2 was common.

I did that for the same reason S4 normally eschews vector movement: Player Involvement.

My players had all sorts of "chores" to do when their ship arrived in-system. They needed to figure where/when they were, they needed to plot a course, they needed to safely secure the jump drive and "light off" the maneuver drive, they needed to perform passive sensor sweeps of their immediate region and (hopefully) identify the various ships they could see, they needed to contact the port, they needed to contact their contacts, they needed to arrange for berthing, cargo handling, and passenger services, they had a lot of stuff to do and every player had a part in it.

I had a list of general tasks for each player, some needing to be rolled and some not. The whole process, which I didn't do every time the players arrived somewhere, was a way for me to divulge information as the GM with blandly reading it to them. Just as my players had to "work the street" in port to learn what they wanted to know, they also had to "work the system" during their inbound voyage.

When space combat occurred, and despite using HG2, my players used various skills to effect the outcome of various activities within each round, either positively or negatively. Pilot and navigation skills affected initiative, agility, computer affected computer ratings and gunnery, gunnery affected gunnery, engineering affected agility and power supplies, and other skills were used in other ways. No one at the table was idle during a space battle because, like S4, I made sure that everyone had something to do and that the something they were doing counted in some fashion.

In the end, the decision of whether to use vector movement or not depends on the needs to the group and whether vector movement will add fun to their gaming experience.


Regards,
Bill
 
If he jumps an inbound, he's within 10 diameters at end, or really close to it; nearly automatic misjump if he jumps out, and guaranteed intercept by local forces if he doesn't.

The example was a 2 day in-system trip.



Gents,

First things first. S4, you really need to play out a couple interception attempts in Mayday and/or LBB:2. Really as in really, really, really, really, need to.

Why would you think I haven't? I've played lots of that type of thing. Yes, it's a bitch to match vectors. Pirates can't attack every ship that way. They have to wait for the right one.

Typically, a pirate disguises himself as a merchant, and then trails a vessel with a lower class M-Drive. Sometimes, the pirate starts at a different locations and figures where, along the target's course, they can intercept.

The pirate is usually found out long before the attack begins, but at that vector, as I said in the post above, there's not much anyone can do about it.
 
The problem, Which you ARE IGNORING, S4, is that the pirate intercepting the inbound merchant is in a lose-lose situation; even if he does get the cargo, the locals don't have to match vector... just saturate him with missile fire (which, under CT Bk2, is even more deadly than in later editions...) and prevent the pirate's escape.

He's toast. Flip him over, he's DONE on that side. He's just as constrained by the physics as his target, and going into a zone from which escape is suicidal.
 
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