Thursday, April 10, 2008

Scan ops on the Bridge

EDIT: I want to review this in the light of my embrace of the likelihood that ships won't ever be *invisible* in space, at interplanetary distances... ships will see each other long before they're in targeting range.

I think that the system outlined below might well work, somewhat expanded, for determining who spots whom first and identifies them as a threat/target. That could happen well beyond three lightseconds - Spotting a ship, judging its mass and power output, its vector. Of course, really identifying a threat - noting that object A has been correcting course to intercept - is dependent on object A having noticed your ship already.

I've often been a little nonplussed with LBB2's highly deterministic detection rules. So have lots of folks... and I've wanted to work a version of them that kept the spirit of LBB2 (and the key ranges) while giving a little more flesh to them.

Also, I've thought that having the navigator show up, sit at the keyboard a few minutes, run up a jump program, and return to his berth didn't rate the pay a navigator gets. Put that man to work! When the ship's insystem, the navigator is the Scan Op.

It's also struck me that in the ship design sequence, both for LBB2 and High Guard, there's no mechanic for differentiating military from civilian sensors. So I'm saying that the difference is up to two things: Computer size and eyeballs. Military and active duty scouts are able to extend their scan range because they have bigger computers and more dedicated staff on duty to stand watch than most commercial vessels.

So, when an encounter is occurring:

Each ship/fleet rolls 2D:
+ combined nav skill on duty
-2 if no dedicated navigator on duty
+/- relative computer size
Ships in communication can combine their modifiers.

Modified roll
Target ship attitude standard 4 6 8 10 12 15
silent 6 8 10 12 15 18
silent/orbit 8 10 12 15 18 21
Range of encounter range km 18750 75000 150000 300000 600000 900000
range mm 187.5 750 1500 3000 6000 9000
range bands 2 8 15 30 60 90

Low number determines minimum range of encounter; high number determines maximum range; higher roll begins the encounter as intruder and may choose any starting range between the maximum and minimum. If difference between rolls is greater than 3 then surprise is achieved, and native may not reprogram computer before combat begins.

Alternatively, the ship achieving surprise may elect to avoid the encounter entirely by breaking off or jumping; If there is no surprise, the intruder may not avoid the encounter but will have the advantage in attempting to break off or jump.

So: ship A with a solo pilot on duty with Nav 1 and a Model 1/bis rolls 7, +1 for nav, but -2 for no dedicated navigator = 6

Ship B with a pilot w/ no nav skill, but a navigator on duty and a model/1 computer with nav 1 rolls 7, but +1 for a dedicated navigator:= 8

(Both ships have the same computer rating, so that doesn't signify here.)

Assuming both ships to be running standard, Ship B may choose to begin the encounter as intruder between 75000 and 150000 km.

If B were running silent, A would only be able to detect her at a range of 18750km, and so ship B would be able to start the encounter as intruder between 18750 km and 150000 km.

So: ship A with a pilot w/ no nav skill, but a navigator on duty with nav 1 and a Model/1 rolls 7, but +1 for a dedicated navigator:= 8

Ship B with a pilot and no nav skill, but a navigator on duty with nav 2 rolls 7, but +2 for the navigator:= 9

But! Ship B also packs a Model /3 computer. So Ship A's roll goes down to 6, and ship B's goes to 11.

Assuming both ships to be running standard, Ship B may choose to begin the encounter as intruder between 75000 and 300000 km, and achieves surprise. Chances are, Ship A is toast.

Note that if the navigator is on the ship, but not on the bridge and on duty, no modifier is allowed.

Ships in close communication can combine their scan information: Fleet scan is effective a LONG way past laser range... two ships with nav-2 on board and computer model 3 get a +6 when attempting to detect a ship with a mod/4 computer.

An Aside:
Ships running silent may have difficulty starting their drives quickly. In the movement phase, Roll 8+ separately to engage the power plant and maneuver drive; one roll per engineer on duty, +engineering skill. Note that most merchant ships will not have the staff on hand to go from cold to hot in one combat round. If the maneuver drive is successfully engaged but the power plant is not, the maneuver drive will fail.


Blogger Omer Golan said...

Keep in mind that in most group (i.e. non-solo) games, the referee would like to conceal the sensor roll result from the players - they shouldn't know about a ship they haven't successfully detected. So the Referee might make the throw behind the GM screen when an enemy ship closes in on the PCs. In addition, the player manning the sensors could always declare that he's actively scanning for other ships - in this case he'll roll for himself and the ref will roll in secret for any concealed enemy ships.

And remember that the difference in computers should be added or subtracted from one side only - if to add it to the player with the better computer and subtract it from the player with the worse computer, you'll end up applying it twice. An alternative approach would be to give a set DM to the roll per computer model - say, half the Computer Model rounded down.

9:43 AM  
Blogger Festeria said...

Good points. Perhaps the thing to do is to simply add the computer number to the roll, to avoid double application of the mod, and to avoid tipping off the size of the opponent's computer to the PC.

9:47 AM  
Blogger Omer Golan said...

You could also use similar rules to detect obscure data about a planet (such as locating anti-ship missile batteries or hidden bases) and to gather detailed information about a nearby object (life indications, energy distribution etc).

12:41 PM  
Blogger Festeria said...

I like that - rolls on comp and nav work nicely for that kind of scanning.

1:10 PM  
Blogger Festeria said...

I've smoketested it a little, and I think I need to tighten it up a little, maybe have it be a 1-die roll instead of two, A)to have it reflect the commercial/military ranges a little more closely and B) to have the mechanics a little closer to the surprise roll in LBB1 ground combat. It works pretty well, generally speaking, but there's too much variation in range between similar ships, and it's too easy for a commercial ship with only a token navigator to get detection well into the 1-2 light second range.

The benefit of being able to scan easily into the 2LS ranges ought to be at the cost of having one or two extra pairs of eyes on the bridge doing nothing but scan.

12:13 PM  
Blogger Omer Golan said...

Another possibility is to give each sensor system (or computer model) a different base sensor range, with negative DMs for every addition increment; this way military sensors (or better computers) will detect other ships more easily on longer ranges.

6:49 AM  
Blogger Omer Golan said...

I am anxiously awaiting your next blog post - this blog is cool and very inspirational for Traveller stuff.

1:30 PM  

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