Re: Spotting ships - Was: Spelljamming speed, and invisibility

>From: Paul Westermeyer <westermeyer@????????.net>
>Subject: [SPELLJAMMER] Spelljamming speed, and invisibility
>Date: Sat, 4 Mar 2006 09:42:11 -0500
>
>Can ships see each other while at spelljamming speed?  The canon implies 
>yes, we have numerous examples of ships following each other at 
>spelljamming speed in the novels and the rulebooks.  Spelljamming speed is 
>extremely fast ( ?????) and I would think seeing another ship with the 
>naked eye would be difficult, but I think possible.

I think that the probability that someone on a spelljamer can spot another 
ship would be dependent on the relative velocities. Ships going in the same 
direction would have better chance of spotting each other.

In the examples you mention, one ship seems to be trying to chase the other. 
As all ships travel at spelljamming speed, I would suggest that a ship you 
were chasing would initiallly start off dead ahead of you. With both your 
ships heading in the same direction, the tracked ship should maintain a 
fairly constant position against the stars on the shell of the crystal 
sphere. The ship would also be a fairly constant size (because you can not 
catch up or get left behind).

In an ideal world following a ship would be easy. Two things would 
complecate the situation and make it possible to loose track of a ship.

The first problem is a slight difference in direction. If the ship you were 
chasing turned half a degree to the left the turn might not be enough to 
make it drop to tactical speed. Over time it would slowly move away from 
your heading, sliding off to the side. If your lookouts noticed the change 
in heading, then your helmsman could make a correction. However, if they 
failed to see it, the ship would get further and further to the side. 
Eventually the error would be so bad that the distance between your ship and 
the other ship would increase. The ship would then be harder and harder to 
spot and would eventually be too far away for non-magical tracking.

The second problem concerns objects that slow ships to tactical speed. 
People generally assume that a helmsman "trys" to avoid every thing in 
space, but a ship that was being chased could actually benifit from being 
dropped to tactical speed. Imagine a chased ship that sees a small asteroid 
ahead of it, or stumbles into something by chance. The helmsman could change 
to a heading that puts the object between them and the person chasing them. 
They could then accelerate off in a new direction. (It is a to imagine ships 
moving through space, so I'll use skaters as a simpified example. Imagine 
you are on roller skates chasing a distant skater. It is night and you can 
just about see them. Suddenly as they are passing a lamp post they grab the 
post, swing around it and start skating off to the left. Do you think you 
could spot that? If you had to slow down to change direction, do you think 
they would get ahead of you? Do you think you could make up a bit of time on 
the turn? Now change this to a ship moving in three dimensions. The chased 
target can spin off in any direction.)

I've not noticed a spelljamming check rule for 3e yet. Lets see if we can 
thrash one out on the list.

While there is no cover on concealment to hide a ship in, I would argue that 
the dark background of wildspace provides concealment that a helmsman can 
use to attempt to hide.

I'm thinking of a helmsman turning the ship, and therfore creating a DC to 
spot, which the lookout on the following ship has to beat. There are seven 
things that *might* need to be involved in this formular:

1) The caster level of the helmsman decides how much push a ship gets at 
tactical speed, so it is one thing we might think of using as a modifier. 
While this choice sounds good it doesn't take helm type, or manouverabilty 
into account. The main problem with using a caster level for this 
calculation is that some helms use other power sorces and have SR but no 
caster level. I'd suggest ignoring caster level.

2) Major helms have more push per level than minor ones, so that is 
something else that we could use. We could use an adjustment like "+2 for a 
major helm". However, if we *are* going to use SR, then the helm type is 
already factored in and this sort of adjustment would be a repetition. Again 
I'd suggest ignoring helm type.

3) Ships Raiting has always been a factor at tactical speed. A high speed 
turn would involve slowing to tactical speed, changing direction and then 
accelerating. Although small angle turns would not use tactical speed (and 
would not imply that SR was a factor) this is a ready made modifier for 
every helm type. I would definately want to use SR if possible.

4) Manouverabilty Class alters how much a ship can change direction in a 
round. This should definately be in there somewhere, as ships that are more 
manoeverable should find it easier to skip off in new directions. This could 
perhaps be something along the lines of "+1 or +2 for each class above the 
worst class". I'll come back to this in a bit.

5) The apparant size of the helmsman's ship. Ships are probably gargantuan 
(-12 to hide or collosal -16 to hide). You could use the normal distance 
modifier from the spot skill (-1 to spot per 10 feet of distance). I'll come 
back to this in a bit as well.

6) A ship that changes heading would change from a small point (that could 
be mistaken for a star) to a moving point (which is more easily spotted). 
The standard DC adjustment for fast moving characters trying to hide is -20.

7) Finally, the apperance and illumination of the ship alter the ability of 
its helmsman to hide it. A dark hull, dark decks and dark sails would add to 
the spot DC. Open lanterns would subtract from it.

I'm coming to think that a combination of ships SR, MC distance should be 
used (with modifiers for the darkness of the ship). I've just looked at the 
2e Fast Play rules on BtM (which you, yourself wrote! LOL):

http://spelljammer.org/rules/fastplay2e.html#ShipToShipCombat

Lets come back to MC first and deal with distance second.

Two columns in the "Maneuverabilty Class" table interest me. The first is 
the "Hex Face Change per round" column, the second is the "Initiative 
Modifier" column.

Hex Face Change only has useful numbers down to class D but extending the 
mathmatical progression you get:

MC HFC Modifier
A   4
B   3
C   2
D   1
E   0
F   -1
G  -2*

The Fast Play Rules state a class G ship can't turn during combat. I'm not 
sure why as I don't have my books with me. I would have thought that 
everything would be able to change direction at some sort of rate.

Initiative has been inverted in the new 3e rules (big is better instead of 
small is better) so if we use the Initiative Modifier, we would probably 
multiply what you wrote by -1 to give:

MC IM Modifier
A   3
B   2
C   1
D   0
E   -1
F   -2
G  -3

I prefer the (adjusted) IM modifier as it seems to balance things out better 
(the middle class D is also the middle number).

So far I'm thinking of making the helmsman's hide DC d20+hide ranks+SR+MC 
adjustment.

The range from this is d20 (1 to 20) + hide ranks (0 to 23 - for a non epic 
character) + SR (1 to 10) + MC adjustment (-3 to 3). This is equal to (-1 to 
56).

Coming back to the apparant size of the ship I forget how large the size 
categories are so I'll assume (for now) that they are collosal (-16 to 
hide). This reduces our above target range down to -17 to 40.

The fast movement penalty (-20 to hide) reduces this targe range further 
down to -37 to 20.

While 20 looks a bit high, it would only apply to helmsmen with a caster 
level of 20 and maximum ranks of hide. Most characters would have much lower 
DCs when they turn their ships to evade following ships. Most of the DCs 
would be less than zero.

Now lets switch over to the lookout. They roll a spot check against the 
above DC with the following modifiers to their roll:

-1 per 10 feet of distance
-5 if distracted

Distractions could include clouds of pepper or dust, which a chased ship 
could fire backwards.

The real killer for a lookout is the distance modifier. Lookouts on ships 
close to the ships they are chasing would find it harder to spot ship the 
further away they were. However, as the distance modifier turns into -1500 
per hex distance. The spot roll gets virtually impossible at the minimum 
distance ships can be apart without dropping to tactical speed (12,500 
yards).

(This also makes falling overboard even more dangerous as spotting someone 
seems virtually impossible at range.)

Perhaps we need a different sort of distance modifier that reduces the spot 
check more slowly. What do you think?

>Paul Westermeyer,  westermeyer@????????.net
>
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