CT Only: Agility and acceleration

[AnotherDilbert]

You forget there's anotehr definition of Agility:

And they seem not to be 100% coincident (or at least subject to different interpretations)...

This is the clarification:

Rules and Rulings
Starship design and construction, and subsequent space combat, are governed by the rules in Traveller Book 5, High Guard. The following rules clarifications are presented to more carefully state some of the concepts of that book.
...
AGILITY
Agility is a measure of the amount of energy available to the ship's maneuver drives, even when other operations are in progress.

So, a ship built as MD6 PP12 who has received 6 hits on its PP is unable to accelerate, despite having still MD 6 with a matching PP?

If you are using the output of the remaining PP-6 to power weapons and screens, there is no power left for the M-drive, so yes.
If you declare Emergency Agility you pour the power into the M-drive first, and you can manoeuvre at 6 G.

 

[TamsinP]

So, a ship built as MD6 PP12 who has received 6 hits on its PP is unable to accelerate, despite having still MD 6 with a matching PP?

It can accelerate if some/all of the remaining PP output is used for manoeuvre rather than weapons, screens, etc.

 

[McPerth]

This is the clarification:

Would you be kind enough to tell me where is this from?

 

[AnotherDilbert]

Would you be kind enough to tell me where is this from?

CT TCS, p12:
AGILITY
Agility is a measure of the amount of energy available to the ship's maneuver drives, even when other operations are in progress.

 

[Grav_Moped]

With a damaged PP, no drive works at all

Read literally, yeah, Book 2 is gonna Book 2.

The fact that neither of the original canon military ships (the Types T and C) has a higher Pn than their other drives suggests that's not the way that rule was intended to be interpreted.

Then again, neither is powered to enable laser double-fire either, so it could have been a lapse of imagination. Not that this would be dispositivr either way....

 

[AnotherDilbert]

Read literally, yeah, Book 2 is gonna Book 2.

I still can't quite understand why so many people are so fond of it... Sure it's the first system, but it's far from perfect.

The fact that neither of the original canon military ships (the Types T and C) has a higher Pn than their other drives suggests that's not the way that rule was intended to be interpreted.

It's not that bad, power plant hits are rare: a roll of 2 on 2D is 1/36. M-drive hits are twice as likely.

Then again, neither is powered to enable laser double-fire either, so it could have been a lapse of imagination. Not that this would be dispositivr either way....

They are not optimised warships, just some random ships to use.

How do you get players interested in designing their own ships, if they can't design better ships?

 

[Grav_Moped]

I still can't quite understand why so many people are so fond of it... Sure it's the first system, but it's far from perfect.

Vectors. The rest is details.

It's not that bad, power plant hits are rare: a roll of 2 on 2D is 1/36. M-drive hits are twice as likely.

But any pp hit is a mobility and/or mission kill. Plausible on a merchant, unreasonable for a nominally military ship.

They are not optimised warships, just some random ships to use.

How do you get players interested in designing their own ships, if they can't design better ships?

Heck, even the Corsair doesn't do it. It seems to have not occurred to anyone!

Which is weird.

 

[AnotherDilbert]

Vectors. The rest is details.

Vector movement sounds great, but how often has people played tricky scenarios where it actually matters, and been successful at it? It just takes too much time and effort.

I looked at it and thought "Great", then I realised that I was supposed to track every single missile individually, slowly put down the book and thought "Unworkable". Then I bought LBB5 and never looked back...

 

[Grav_Moped]

Vector movement sounds great, but how often has people played tricky scenarios where it actually matters, and been successful at it? It just takes too much time and effort.

I looked at it and thought "Great", then I realised that I was supposed to track every single missile individually, slowly put down the book and thought "Unworkable". Then I bought LBB5 and never looked back...

I get that, but see it as using the right rules for the right situation and narrative effect.

 

[McPerth]

If you declare Emergency Agility you pour the power into the M-drive first, and you can manoeuvre at 6 G.

But even if you declare emergency agility, if your PP just matches your MD, the PP would probably not be enough to give it this Agility level (as other things also use power, as your screens or computer), and yet, by definition, it is matched...

It can accelerate if some/all of the remaining PP output is used for manoeuvre rather than weapons, screens, etc.

No, according the rules... If you have a -6 to Agility due to PP damage, even underpowering your other power consuming systems your Agility would be 0 (unless Emergency Agility isused).

If your acceleration capacity (even without violent maneuvers) is determined by your Agility, this ship cannot accelerate at all without using Emergency Agility.

Sure it's the first system, but it's far from perfect.

No system is... (BTW, thanks for your answer about the origin of your quote. As it had no unquoted text, I could not quote it)

Vectors. The rest is details.

Quite good for one or two ships per side, but when you have whole fleets...

 

[McPerth]

In fact, I mostly understand your arguments, and I guess I’m not being able to explain mine, but I’ll try anyway…

As I already stated, I’m mostly a MT man, being the current version when I could have it (Traveller products were not easy to obtain in Barcelona by then, nor now for wat is worth), and it can have influenced my view. MT movement rules are horrible (the fact you can stay at the same square by ·circling though it, even if you had a vector speed of 12 and just 1G acceleration being a paramount example), but their narrative explanations used to be quite good (albeit rarely reflected on rules).

On them (MT:SOM, IIRC), it is explained that thrusters (the usual MD at TL11+) and gravitic MDs (for TLs 9-10) are able to also give you lateral thrust, albeit at reduced capacity (25%, IIRC). It is also said (when answering a Q&A about how could a 1G ship take off from a 2G gravity planet) that they can be overloaded up to 400% for short periods of time). It also talked about direction changes being through spinning disks in the ship’s centre of gravity, but I’ll leave this aside). I see all those arguments perfectly usable in CT too, as the principles are quite close.

Adding all this together, I saw Agility as the capacity to use those overloads in lateral trust for random direction changes, while keeping the acceleration all along the way, and this overloading needs more power.

When transferring this to CT, my view was MD number means the Gs the ship is able to accelerate with the base power given by the PP (hence the need for the PP to match the MD), while the extra power given to them for Agility means also those overpowering lateral trust.

Of course, having seen the MT explanations before entering in more detail to CT may be a boon (as those explanations were already available) or a curse (as it gave me a different view than the assumed before them, and so the standardized ones).

The fact that where ship’s movement and acceleration is explained (LBB2) doesn’t talk about Agility, and where Agility is defined (LBB5) doesn’t say a dime about acceleration (and after all, the game effect is negligible, it any) doesn’t help, and I guess leaves way to different interpretations, all influenced by the player’s background and previous gaming experience (and probably by the “consensus” among their playing communities, which use to be influenced by the interpretation their first player made of the rules)

 

[mike wightman]

HG ship combat damage affects agility rather than weapons because it would be impossible to track EP lost due to PP hit to every weapon system.
You keep missing the most important bit of the HG quote which TCS clarified
Agility is the ability of a ship to make violent maneuvers and take evasive action while engaging hostile targets.

So agility is what you have left after weapons and screens. Emergency agility is what you get when you stop shooting and powering screens and instead divert EP to the m-drive.

If you want an agility 6 combatant you build it with a pp that can power everything and have enough EP for agility 6, so a pp of 9 or higher is common in my TL15 warships.
If they rake a pp hit then agility is reduced because it is easier to reduce agility than to truy and calculate how to distribute the lost EPs to every weapon and screen system.

A note on LBB combat - one of the jobs of the engineer in the event of a pp hit is to shoot the m-derive so its rating is reduced thus the pp and m-drive can still function at a reduced number

 

[kilemall]

While we are on the power topic, let me tell you my power allocation mechanic.

Instead of SFB system allocation forms, I use command priority syntax for which systems get power to what level for the turn. So the command might be

Agility-3
Screens
Spinal
50% lasers
All meson bays
Repulsors
Rest of lasers
Fusion Guns

The power is then allocated from top to bottom in the order listed. If the total power available runs out before all systems are charged, then they are not operational for the turn. This can happen if the power plant takes more damage then the other EP using systems.

This is a tactic, a preset power prioritization routine like those ‘attack pattern delta’ type commands from Star Trek. The crew is trained up and appropriate computer commands built to execute the tactic.

The agility number can be changed dynamically, otherwise the power is allocated in total for each system in priority order before the next one.

Each crew and captain of even scout or merchant ships has an assumption of the equivalent of Ship Tactics-0, which yields the emergency agility priority to maximum tactic and one standard operating priority tactic.

Typical High Guard naval captains have Ship Tactics-2, each level of that skill yields two tactics so most navy ships can do 4 tactics on their own plus the two default ones.

In addition Fleet Tactics skill yields two more tactics per skill level, which are practiced by all ships in a fleet. So the behavioral options/quirks of a ship and the fleet they belong to are largely determined by the drills their captain and admiral institute.

Ships do not change their tactics because of a new captain, they must go through a drill period to learn and practice new tactics.

Jack-of-All-Trades yields two tactics in addition to the defaults but get no bonuses in initiative rolls or more tactics with higher skill.

 

[AnotherDilbert]

But even if you declare emergency agility, if your PP just matches your MD, the PP would probably not be enough to give it this Agility level (as other things also use power, as your screens or computer), and yet, by definition, it is matched...

It's a very simplified system for dynamic allocation of power. You basically have two settings: Weapons first, or everything to the M-drive.

Does that fit every scenario? No.
Is it simple and works? Yes.

If your acceleration capacity (even without violent maneuvers) is determined by your Agility, this ship cannot accelerate at all without using Emergency Agility.

"Emergency Agility" is basically turning weapons and screens off. It's the normal mode outside combat.

 

[AnotherDilbert]

In fact, I mostly understand your arguments, and I guess I’m not being able to explain mine, but I’ll try anyway…

As I already stated, I’m mostly a MT man, being the current version when I could have it (Traveller products were not easy to obtain in Barcelona by then, nor now for wat is worth), and it can have influenced my view. MT movement rules are horrible (the fact you can stay at the same square by ·circling though it, even if you had a vector speed of 12 and just 1G acceleration being a paramount example), but their narrative explanations used to be quite good (albeit rarely reflected on rules).

Yes, MT is different in some key areas, such as movement and agility.

On them (MT:SOM, IIRC), it is explained that thrusters (the usual MD at TL11+) and gravitic MDs (for TLs 9-10) are able to also give you lateral thrust, albeit at reduced capacity (25%, IIRC). It is also said (when answering a Q&A about how could a 1G ship take off from a 2G gravity planet) that they can be overloaded up to 400% for short periods of time). It also talked about direction changes being through spinning disks in the ship’s centre of gravity, but I’ll leave this aside). I see all those arguments perfectly usable in CT too, as the principles are quite close.

All that is in SSOM, p2-3.
It could be imported into CT, but not what CT rules say:

CT Striker, B2, p41:
A ship with a G rating equal to or less than the planetary gravity may not take part in combat actions except from orbit.

No overloading the drives to land on high grav planets.

Adding all this together, I saw Agility as the capacity to use those overloads in lateral trust for random direction changes, while keeping the acceleration all along the way, and this overloading needs more power.

The problem is that MT agility isn't connected to or limited by the M-drive. You can build a ship without an M-drive, but it would still have an agility rating.

I have no idea what MT agility is, but it not the same as CT agility...

When transferring this to CT, my view was MD number means the Gs the ship is able to accelerate with the base power given by the PP (hence the need for the PP to match the MD), while the extra power given to them for Agility means also those overpowering lateral trust.

Yes, a PP-1 can power a MD-1 to accelerate by 1 G.
No, there is no extra power. Give the MD-1 PP-1 worth of power it will produce 1 G, give it more power and nothing extra happens.
You just have the option to reroute the power to weapons instead, leaving the MD with less power, producing less acceleration.

CT is quite different from MT in this regard.

Of course, having seen the MT explanations before entering in more detail to CT may be a boon (as those explanations were already available) or a curse (as it gave me a different view than the assumed before them, and so the standardized ones).

Each edition has to be evaluated on its own. We might use other editions for guidance, but I don't think we should retcon earlier editions.

 

[McPerth]

All that is in SSOM, p2-3.

CT Striker, B2, p41:
A ship with a G rating equal to or less than the planetary gravity may not take part in combat actions except from orbit.

It could be imported into CT, but not what CT rules say:
No overloading the drives to land on high grav planets.

As I don't own Striker, I had never read this. So a 1G ship cannot take off from a 2G planet in CT?

Each edition has to be evaluated on its own. We might use other editions for guidance, but I don't think we should retcon earlier editions.

In general I'd agree with you, but MT is a kind of "advanced CT", and in fact it's unplayable unless you know something about CT (at least without the errata and its clarifications), as many poibnts are too uncelar, but can be taken from CT.

 

[Carlobrand]

I confess I am enjoying this. A bit puzzled at times, but I am enjoying this.

Agreed that CT agility and MT agility are different beasts, inasmuch as MT agility does not care about the drive rating - unless I've missed something or there was errata published. MT was rather bad about errata.

So what precisely is agility doing? It's using excess energy after weapons and so forth to "make violent maneuvers and take evasive action", causing the attacking weapon to miss or otherwise fail to do damage. I think - I hope - that we agree the maneuver drive, when fed excess power from the power plant, is what's making the craft capable of these violent maneuvers. The debate seems to be whether the craft can still accelerate normally when the maneuver drive does not receive excess power.

See, here's the thing. If I have a power plant 6 and a maneuver drive 6 and no other power-using systems, then I have agility 6: all that power is going to my maneuver drive. If I slap on lasers and energy weapons and such and divert all that power to them, then I no longer have excess energy for my maneuver drive and now have agility 0.

Here's where the problem starts: if my maneuver drive is still delivering 6g acceleration, then I am creating energy from nothing. The acceleration of my craft, even in a straight line, represents an increase in kinetic energy - energy that came to me free. My power plant isn't producing it; all my power plant's energy is going to weapons.

Or else we're saying my power plant is producing undisclosed power that let's my drive deliver 6g but not deliver violent maneuvers since it's not "extra". Except, I could build a killer satellite with no maneuver drive and that same power plant 6 and power the same weapons, but now I don't get to use that undisclosed power. Why not?

Here's the other problem: given 6g acceleration, I can still do violent maneuvers, extra power or not. My attitude jets or my gyroscope turn my ship, 6g maneuver burst, turn the ship again, another 6g maneuver burst, you can't stop me from making these maneuvers so long as I can use my little attitude jets to change my ship's facing. So, what is agility if these random burst of acceleration in random directions doesn't count?

 

[Krikkitone]

I confess I am enjoying this. A bit puzzled at times, but I am enjoying this.

Agreed that CT agility and MT agility are different beasts, inasmuch as MT agility does not care about the drive rating - unless I've missed something or there was errata published. MT was rather bad about errata.

So what precisely is agility doing? It's using excess energy after weapons and so forth to "make violent maneuvers and take evasive action", causing the attacking weapon to miss or otherwise fail to do damage. I think - I hope - that we agree the maneuver drive, when fed excess power from the power plant, is what's making the craft capable of these violent maneuvers. The debate seems to be whether the craft can still accelerate normally when the maneuver drive does not receive excess power.

See, here's the thing. If I have a power plant 6 and a maneuver drive 6 and no other power-using systems, then I have agility 6: all that power is going to my maneuver drive. If I slap on lasers and energy weapons and such and divert all that power to them, then I no longer have excess energy for my maneuver drive and now have agility 0.

Here's where the problem starts: if my maneuver drive is still delivering 6g acceleration, then I am creating energy from nothing. The acceleration of my craft, even in a straight line, represents an increase in kinetic energy - energy that came to me free. My power plant isn't producing it; all my power plant's energy is going to weapons.

Or else we're saying my power plant is producing undisclosed power that let's my drive deliver 6g but not deliver violent maneuvers since it's not "extra". Except, I could build a killer satellite with no maneuver drive and that same power plant 6 and power the same weapons, but now I don't get to use that undisclosed power. Why not?

Here's the other problem: given 6g acceleration, I can still do violent maneuvers, extra power or not. My attitude jets or my gyroscope turn my ship, 6g maneuver burst, turn the ship again, another 6g maneuver burst, you can't stop me from making these maneuvers so long as I can use my little attitude jets to change my ship's facing. So, what is agility if these random burst of acceleration in random directions doesn't count?

Agility could be the attitude jets/gyroscope etc. that rotate the ship. or whatever allows you to make the acceleration more than 1 dimensional.

 

[Spinward Flow]

"Emergency Agility" is basically turning weapons and screens off. It's the normal mode outside combat.

LBB5.80, p39:
Emergency Agility: A ship may be declared to be using its emergency agility during the pre-combat decision step. If so, the ship may not fire any of its energy consuming weapons (all but missiles and sandcasters), but its agility becomes equal to its maneuver drive or its power plant number, whichever is less. The ship may still use its computers and screens. This tactic is especially useful when breaking off by acceleration.

See, here's the thing. If I have a power plant 6 and a maneuver drive 6 and no other power-using systems, then I have agility 6: all that power is going to my maneuver drive. If I slap on lasers and energy weapons and such and divert all that power to them, then I no longer have excess energy for my maneuver drive and now have agility 0.

Here's where the problem starts: if my maneuver drive is still delivering 6g acceleration, then I am creating energy from nothing. The acceleration of my craft, even in a straight line, represents an increase in kinetic energy - energy that came to me free. My power plant isn't producing it; all my power plant's energy is going to weapons.

Here is what is ACTUALLY happening.

Power Plant code must at all times exceed Maneuver code.
You are not allowed to design a Power Plant-3 for a Maneuver-4 drive, for example.
WHY?

Answer, because you need a Power Plant of an equal or higher code number to the Maneuver drive for the Maneuver drive to deliver its full acceleration in Gs ... whatever that number is (1-6).

But then what's the deal with EPs and Agility?
How can a craft with Maneuver-1+ and Agility=0 ... accelerate at all?
Power Plants produce enough energy to power Maneuver drives up to their code number BASELINE.
A Power Plant-4 will ALWAYS under all circumstances deliver sufficient power to a Maneuver-4 drive to produce 4G acceleration under all conditions, regardless of circumstances (until the power plant is damaged or runs out of fuel, of course).

But what about EPs and Agility?

Maneuver and Agility refer to different things.
That's like trying to say that acceleration, velocity and speed are all the same things ... when THEY ARE NOT.
A Power Plant-4 will ALWAYS under all circumstances deliver sufficient power to a Maneuver-4 drive to produce 4G acceleration under all conditions, regardless of circumstances (until the power plant is damaged or runs out of fuel, of course).
The ability of the maneuver drive to produce acceleration (at all) is "baked in" to the power plant minimum requirement.

Then what are EPs?
And what is Agility?

EPs are the ADDITIONAL ENERGY the power plant produces for all other energy consuming purposes AFTER meeting the minimum requirement needed for the full acceleration output of the maneuver drive. That extra energy can be allocated to weapons, screens, computers ... and/or agility.

Maneuver is the ability to "GO FAST" in a straight line.
Agility is the ability to "TURN FAST" to alter course away from straight line movement.

I would hope that everyone reading these forums has enough Geek Cred™ to recognize this quote:

Or I could use this historical example of a craft that flies REALLY FAST, but can't TURN to dogfight ...

So what does this mean in Traveller space combat terms then?

A starship like a Gazelle-class close escort with its Power Plant-5, Maneuver-5 and Agility-0 can maneuver at 5G in a straight line, but it can't TURN worth spit with its weapon systems active. Power down the weapons and pour all the EPs the power plant can produce into the computer and maneuver AGILITY and the starship can TURN with an Agility-5, but it can't attack anything while doing so.

Maneuver = Go Fast
Agility = Turn Quick

If you can go really fast, but can't turn ... a more nimble opponent (who has higher agility) can take advantage of your inability to follow highly agile movements and escape. They turn around while you can't. They go a different direction while you can't. They escape because you can't match their course changes. You go REALLY FAST in the wrong direction and can't recover quickly enough to re-engage.

This is why Agility is the important factor for an evasive plan of action such as Breaking Off By Acceleration. The craft with "better agility" are able to "shake" their pursuers by turning away when the pursuit can't. Higher agility "defeats" lower agility, even if the lower agility can achieve better acceleration. That's because the higher agility is "more responsive" to changes in vector, while the lower agility is "sluggish to turn" and change vectors.

If the pursuit is in a straight line (like a race to a goal) then agility is NOT A FACTOR and the superior acceleration will win.
If a pursuit relies on agility to "shake" a pursuer, then agility is the DECIDING FACTOR because the higher agility craft can move in ways that force a lower agility but higher acceleration pursuer to "waste" a lot of their acceleration by not being able to follow the "chop and change" course changes of the higher agility craft ... putting the lower agility craft at a disadvantage that cannot keep up with and remain in contact with the higher agility craft. Hence, higher agility "wins" Breaking Off By Acceleration contests.

Power plants produce enough power to provide full acceleration (in a straight line) from associated maneuver drives.
Power plants ALSO produce additional energy IN EXCESS of this minimum needed for full maneuver drive acceleration IN A STRAIGHT LINE.

However, TURNING to change course headings in a combat meaningful way requires ADDITIONAL power to the maneuver drive than the default minimum ... and this additional power is where the EPs allocated to maneuver drives for the purpose of agility (not acceleration, per se) come into play.

A power plant that has NO ADDITIONAL POWER DEMANDS other than exclusively the maneuver drive will produce an agility rating that matches the acceleration Gs of that drive.

Power Plant-4, Maneuver-4 ... no other EP consuming systems (weapons, screens, computers) ... will also have Agility-4.

It's when you start adding on additional power consuming weapons, screens and computers that this reserve of "extra power" starts getting diverted away from the maneuver drive, reducing agility (unless if you increase the size and power output of the power plant). Acceleration in a straight line remains the same, but combat agility/the ability to turn (on a dime) suffers. The craft becomes less and less responsive to pilot commands for vector changes. You can still power "forwards" at full Gs of acceleration, but as agility goes down, the power available to turn and change course, to fly in different directions goes down.

If you only want to accelerate in 1 direction (forward) then agility is superfluous.
If you want to acceleration in ANY direction, not just 1 ... then agility is paramount.

Maneuver = Go Fast(er)
Agility = Turn Quick(er)

Confuse these basic concepts at your own peril.

 

[Spinward Flow]

Agility could be the attitude jets/gyroscope etc. that rotate the ship. or whatever allows you to make the acceleration more than 1 dimensional.

Finally, someone gets it.