There have been a number of implementations of Tractor Beams, a 'staple' in
SF, posted on the Web over the years, but for some reason, they've been missed
out of the WDA...
A good selection are posted on the The Unofficial Full Thrust WWW Page:
http://www.homegame.org/siefert/uftwwwp/index.htm
Although these designs pre-date the publication of Fleet Book 1.
Using these as a starting point, I think Adam Delafield's suggestion (the last
one on the tractor beam page on the UFTWWWP page) is a good suggestion for a
simple tractor beam rules:
[Begin Quote]
From: Adam Delafield <A.Delafield@bolton.ac.uk>
Most of the ideas about tractor beams give a thrust rating on the enemy ship
opposed to it's movement. However, I've never seen tractors as being so
subtle. The idea of tractors seems to me to be to grapple an opponent and drag
them closer.
-------------------------------------------------------------------
How about this for an idea. Tractors are rated at x, where x is half the
distance the tractor can drag the FIRING ship.
At the end of movement, any ship that has a successful tractor 'lock' on a
ship can move that ship a set distance. These distances are as follows. Just
what constitutes a lock, and how one is achieved has also got to be figured
out.
When firing at a ship which is a CLASS smaller, move the target ship 2x
directly toward the firer.
If the ships are the same class, both move x toward each other.
If firing at a ship of a larger class, the firer is moved 2x toward the
target.
-------------------------------------------------------------------
And another idea.
Tractors simply dissipate kinetic energy. Any ship hit by a tractor looses an
amount of velocity dependant on it's class (down to zero. If a ship is in
reverse it GAINS velocity up to zero).
Capitals loose 1 Cruisers loose 1d6 Escorts loose 2d6
This would be simplest. I'd restrict this type of tractor to capitals, and
only one per ship. I'd also assume that all capitals get tractors for free,
provided they have at least one fighter bay (assumed to be included in
equipment for landing fighters.) provided the background warrants it.
This would be my favourite option.
+-------------------------------------+--------------------+
| Adam Delafield, I.T. Officer | Bolton Institute, |
| | Eagle Tower, |
| E-mail : ad4@Bolton.ac.uk | College Way, |
| Phone : +44 1204 528851 (ext 3163) | Bolton, UK. |
| Fax : +44 1204 399074 | BL3 5AE. |
+-------------------------------------+--------------------+
[End Quote]
I would call the first option a 'Tractor Beam' and the second a 'Kinetic
Damper' as the old FT ship classes (Escort/Cruiser/Capital) no longer
apply, I suggest the following update:
Simple Tractor Beam Rules
=========================
For the sake of utility, any 'tractor beam' is also a 'Pressor Beam'
(just think what happens if you apply a force on another ship _towards_
yours, but you cannot apply a force in the opposing direction to decelerate it
when it gets close...)
Each Tractor Beam has a rating, which is the amount of 'thrust' it can apply
to a ship of the same mass as the ship mounting the Tractor Beam, at close
range.
Tractor Beams are 'fired' during the Launch Ordnance phase: Tractor beams have
full strength out to a range of 6 mu, and half strength
(round down) out to a range of 12 mu, each further +6 mu halves the
strength again.
Roll a number of D6s equal to the Tractor Beam strength (modified for
range), resolve the D6s as beam dice, but without re-rolls. The total
number of 'hits' inflicted is the 'pull' applied (if the tractor beam is used
in 'pressor' or 'repulsor' mode, apply the 'pull' as a 'push').
If the Target ship is less than half the MASS of the tractoring ship, it is
pulled towards the tractoring vessel per twice the result above.
If the target is half or more of the MASS of the tractoring ship, but less
than twice its MASS, then they are both pulled towards each other by the
result above.
If the target is twice or more of the MASS of the tractoring ship, then the
tractoring ship is pulled towards the target by twice the result above.
This pull will affect the course and speed of the affected ships, and is
applied during the Move Ships phase:
In Cinematic, if the pull is applied through the Fore (F) arc, it is added to
the ship's current speed (in addition to any MD in the written orders). If it
is applied through the FP or FS arcs, then half of the pull is
added to the ship's current speed, and the ship makes a 2-point turn
towards the tractoring vessel (in addition to any MD and manoeuvres in the
written orders). If it is applied through the AP or AS arcs, then half the
pull is
subtracted from the ships speed, and the ship makes a 2-point turn
towards the tractoring vessel (in addition to any MD and manoeuvres in the
written orders). If it is applied through the Aft (A) arc, then the pull is
subtracted from the ship's current speed (in addition to any MD in the written
orders).
In Vector, first move the ship according to its existing velocity and written
orders, then move it according to the effects of tractor beams.
Do not measure its new velocity or move the course marker until _after_
the tractor beam effects have been applied.
In all cases, a repulsor 'push' is treated as a 'pull' from the opposite
direction.
A Tractor Beam requires MASS equal to 5% of that of the carrying ship, per
rating, and has a cost of 5 points per MASS. It has a single arc of fire, for
50% extra cost, and can cover 2 arcs, and for double the MASS
and cost, it can be increased to 3-arc coverage.
################################################
> From Adam Delafield's other suggestion, again, updated to the Fleet
Kinetic Suppression Beam
========================
This reduces the velocity of the target ship.
Targets of less than half the MASS of the carrying ship reduce their speed by
2D6 mu.
Targets of less than twice, but at least half the MASS of the carrying ship
reduce their speed by 1D6 mu.
Targets of twice or more the MASS of the carrying ship reduce their speed by 1
mu.
Targets of four times the MASS or more are unaffected.
In cinematic, the target just slows down, while for vector, realistically,
the target should slow down _relative_to_the_ship_
with_the_kinetic_suppressor_, I suggest that for games using the vector
movement system, the Kinetic Suppressor be treated as a tractor beam, but with
the pull applied to as to try and equalise the vectors of the two ships, split
between the two ships as for the tractor beam.
Other Tractor Beam tech
=======================
Tractor Shears
--------------
This is an anti-tractor beam defence. These work as 'screens' against
tractor beams.
Level of Tractor Shears MASS Required Level 1 2.5% of carrying ship Level 2 5%
of carrying ship Level 3 10% of carrying ship Level 4 20% of carrying ship
Tractor shears have a minimum MASS equal to their level, and cost 5 points per
MASS. They are represented by 1 SSD icon per level, and each icon makes
threshold checks separately (as for screen generators).
Level 3 tractor shears reduce the effectiveness of a tractor beam to 1 point
of pull per 6 rolled, while level 4 tractor shears confer immunity.
Manipulator Beams
CST quoting AD:
> Most of the ideas about tractor beams give a thrust rating on the
This is incomplete, IMO. Tractors are used to 2) hold an opponent at bay, 3)
tow a friendly, and in some genres 4) push an object away or 5) force it to
change orientation.
Re concept 1:
I much prefer MASS of the firing and target ship to be the defining factor of
the tractor power and ability. And, this concept ignores
functions 2-5 mentioned above.
Re concept 2:
I agree with Charles that this is an 'relative inertia sink' rather than a
tractor beam.
Re: Charles' rules:
> Each Tractor Beam has a rating, which is the amount of 'thrust' it can
This I like.
> If it is applied through the FP or FS arcs, then half of the pull is
Forcing the target to turn should be an additional "attack" of the tractor
beam, not a given, especially in Cinematic. Or apply the "tractor points"
rolled on attack to forcing the ship to turn (scaled by
mass. 1 point: 1 clock facing if the target is < 50% mass of tractoring
ship 2:1 if 50%<ratio<200%, 3:1 or 4:1 if ratio < 200%.
You could alternately PSB the tractor beam as a Projected Gravitic
Drive. The cost and mass look right - the same as a main drive. This
also solves the "towing" concept as well: A ship with a tractor can tow inert
masses (dead or willing ships, asteroids, etc) Add the total mass (M) of the
tractoring ship plus
target mass. Dtermine the total mass (T) of Main Drive + Tractor Beam.
Divide T/M by .05 and round fractions down (i.e. - without math -
determine how much thrust a Main drive of mass T can give a ship of Mass
M)
Kinetic Supression Beam is wacky, but looks OK.
Tractor Shears: I think an opposed tractor beam should work as a tractor
shear. It rolls
defensively just as the attacking tractor rolls offensively. If you want
defense to be easier than offense, make the defensive roll 2 dice per point of
Tractor strength.
Spinner Beams - I think this should be an alternate function of tractors
-as noted above.
Icon (silly): A U-magnet (top/bottom = white/black.
Icon (serious) An open V in facing arc with a double arrow pointing into
and out of the V.
Alternate use of Tractor as weapon: Tractor Repulsor Beam: Same range bands as
tractor beam. Same dice as tractor beam Screens hav no effect. Damage
application 1 to Armor (if any), then 1 to hull for each damage row, then
repeat, to represent the effect of the entire ship being shaken apart. Mass
issues: Target <50% Mass of attacker: Damage to target as tractor dice roll
50%<Target <100% Damage to target = half tractor dice roll
100%-200% Damage to Target = half tractor
dice roll;
Damage to Attacker = 1/4 dice roll.
200%+ Damage to target = 1/4, Damage to
attacker = 1/2
In message <B09B73A9-B4FC-11D6-88E7-000393071770@jhuapl.edu>
> Noam Izenberg <noam.izenberg@jhuapl.edu> wrote:
> CST quoting AD:
Actually, I assumed that Tractor beams are always also pressor/repulsor
beams (for reasons I outlined), which covers functions 2), 3) (in conjunction
with the tractor function), and 4).
> Re concept 2:
The reason for tractor beams forcing a turn if applied though a side arc
_in_cinematic_movement_ is an attempt to have a tractor beam that
affects the velocity of the ship, rather than a (less realistic IMHO)
one-off pull/push effect.
Note that, in _vector_ movement, this turning does not occur, and the
movement vector caused by the tractor beam is added to that of the affected
ship.
> You could alternately PSB the tractor beam as a Projected Gravitic
> Divide T/M by .05 and round fractions down (i.e. - without math -
Hmm.. how would this be applied in the game?, enable the tractoring ship to
write orders for its target? (IIRC, one of the suggestions in the UFTWWWP uses
this mechanic).
> Kinetic Supression Beam is wacky, but looks OK.
Tractor shears are inspired by those in the Lensman books - but weaker
(the Lensman version seemed to impart immunity to tractor beams).
> Spinner Beams - I think this should be an alternate function of
I think I prefer the latter - I'll try and draw one :-)
> Alternate use of Tractor as weapon: Tractor Repulsor Beam:
As used by:
From: Charles Taylor <nerik@monkslode.fsnet.co.uk>
In message <B09B73A9-B4FC-11D6-88E7-000393071770@jhuapl.edu>
> Noam Izenberg <noam.izenberg@jhuapl.edu> wrote:
> Re: Charles' rules:
> If it is applied through the FP or FS arcs, then half of the pull is
> Forcing the target to turn should be an additional "attack" of the
> by
> The reason for tractor beams forcing a turn if applied though a side
I understand, but this makes tractors much more powerful in cinematic.
Changing a ships heading by 60 degrees is huge (potentially catastrophic
if there's a planet nearby), as opposed to changing their vector by a few MU
(assuming they're moving at more than a crawl to begin with. I
still think pull/push and rotation should be different functions.
> A ship with a tractor can tow inert masses (dead or willing ships,
> Hmm.. how would this be applied in the game?, enable the tractoring
The tractoring ship writes identical orders for the tower and tow-ee,
adn the two move together.
> Tractor Shears:
> Tractor shears are inspired by those in the Lensman books - but weaker
The Lensman system sounds reasonable as a seperate system to nullify tractors.
If you just want to have a tractor war, then opposed tractors is simpler.
Again, if you want defense to be easier, then give the defending tractor more
dice per point (that way a "defensive" tractor could oppose a "multipurpose"
tractor of twice the points).
> Alternate use of Tractor as weapon: Tractor Repulsor Beam:
> As used by:
That's exactly where it came from, name and all. You could also call it a
Graviton Shear Attack Mode for the Tractor, or Shipquake, or...
BTW, this would have to be useful in anti-fighter and anti-missile modes
as well. Probably as a re-usable scattergun.
In message <08DF6925-B694-11D6-A456-000393071770@jhuapl.edu>
> Noam Izenberg <noam.izenberg@jhuapl.edu> wrote:
> From: Charles Taylor <nerik@monkslode.fsnet.co.uk>
[snip]
> > The reason for tractor beams forcing a turn if applied though a side
Hmm.. how about:
Cinematic Tractor beams
=======================
The effect of tractor beams is applied after movement - 'pulls' move
ships together (which ship moves is based on MASSes, as before), and
modify the ships current speed as before - but do not cause turning.
[snip]
> >> Tractor Shears:
Hmm... I modelled the Tractor shears on the existing screen vs. beam
mechanism - i.e. just use an existing game mechanic.
[snip]
> Zoner Beam Ring (Noam R. Izenberg - watch where you point that
G'day,
> There have been a number of implementations of Tractor Beams,
How did that happen?;)
> Simple Tractor Beam Rules
Makes sense.
> Tractor Beams are 'fired' during the Launch Ordnance phase: Tractor
Good idea.
> Summary of effects
So this is why Voyager never tried to tractor the Borg;P;)
Given that the distance between the two ships closes by 2xpull regardless of
result, was there some firm decision on this point or was it a happy accident?
In vector I wouldn't imagine a lot of defence in the overall end result
(though it would be helpful in gravity wells I'll grant you) is there a subtly
I'm missing in cinematic?
> In Cinematic..if...through...(F) arc, it is
Now that is a pretty impressive turn!
> A Tractor Beam requires MASS equal to 5% of that of the carrying ship,
Ahh let me see if I got this right.
1-arc = 5% per level
2-arc = 7.5% per level
3-arc = 10% per level
????
Couple of questions. 1) does the tractor hold in FTL? If yes you should
probably note you need
either 3-arc tractors or level2 tractors to do it otherwise no-one will
ever bother buying an FTL tug again;)
2) How about ships how try to anticipate/break a tractor lock by
"burning"
off in the opposite direction (assuming their engines hold-out)? You
could have something like
a) If a ship in tractor lock burns at full thrust along a coarse directly
opposite to the tractor beam path then at the end of movement it checks
range to tractor ship and rolls a D6. Range 0-6 a 6 is needed to break
free,
at 6-12mu they need a 5+, at 12-18 a 4+, 18-24 a 3+, 24-36 a 2+, a roll
of 1 always fails. If the roll fails an engine threshold is caused. Is the
roll succeeds the tractor lock is broken and the tractor ship must roll for
that tractor on the current threshold level.
OR
b) If a ship in tractor lock burns along a coarse directly opposite to the
tractor beam path with MD > the pull rolled by the tractor ship then the lock
is broken.
> Kinetic Suppression Beam
I know its a different system, but is there any reason that this 4xMASS
threshold doesn't apply to tractor beams too (if I were captaining a hug
lumbering vessel I may not want a bunch of little ships tractoring me so they
could hitch a ride!)
Cheers
In message <A8877251964B294BAB5BA1FC58B43FED613838@molly.tas.csiro.au>
> Beth.Fulton@csiro.au wrote:
> G'day,
It's a quick'n'dirty approximation, I'm trying to have the tractor beam alter
the velocity of the affected ships, rather than simply moving the closer
together (or further apart). The relative motion is the same, regardless of
the MASSes of the ships, but the relative motion between these ships and any
others in play is not.
> > In Cinematic..if...through...(F) arc, it is
In response to comments from Noam, I've removed this 'turning' ability.
> > A Tractor Beam requires MASS equal to 5% of that of the carrying
Yes - is this too much, do you think? (or not enough).
> Couple of questions.
I'd say No, - you need a FTL-tug to do this.
> 2) How about ships how try to anticipate/break a tractor lock by
Of the 2, I'd prefer the second, OTOH, the tractor beam I've described does
not so much 'lock', but rolls for effect each turn.
> > Kinetic Suppression Beam
Well, I couldn't see any reason to apply such a limit to tractor beams
- more detailed tractor rules could take into account the 'drag' factor
of tractored ships - using Noam's 'tractor tug' rule?
> Cheers
Thanks,
G'day,
> In response to comments from Noam, I've removed this
OK.
> Yes - is this too much, do you think? (or not enough).
I hadn't thought about its merits I was just trying to make sure I had it
straight;)
> Of the 2, I'd prefer the second, OTOH, the tractor beam I've described
OK.
> Well, I couldn't see any reason to apply such a limit to tractor beams
I wasn't necessarily thinking of drag, just wondering why 4x was OK in one
system, but not in the other (this may well fit with the genre ideas they come
from as I'm not a tractor beam aficionado)
Cheers