Traveller Tuesday: Stealth and Hull Coatings

I was looking over the 2e High Guard playtest document -- by the way, how are all you 2e converts doing? Still using 1e for ship generation? How does that make you feel, 6 months on without a ship generation system? -- when I noticed that this version of the rules had multiple options at varying tech levels for stealth. I found this interesting, for a variety of reasons:

1. There's been some re-balancing of TLs and numbers;
2. The lower TL stealth stacks with a higher level version;
3. A TL 10 holographic hull costs exactly the same as a TL 10 stealth coating, only without any of the bonuses, even though you'd think that the ability to camouflage the ship against visual sensors would count for something; and
4. I wondered how I could balance the new rules with the (unofficial) advanced stealth rules in Apparition Class Starship, because those are good rules and prior to the 2e HG playtest, they are the ones I used. 

So obviously I'm going to putting together some House Rules with chainsaws and heresy. Everything that follows after this is decidedly not canon. 

My use of Traveller setting and dress falls under
fair use guidelines for both Mongoose and Far Future Enterprises.

NOTE: These rules have not been playtested and are a work in progress. 

They may be changed as necessary!

TL 8 Emissions Absorption Grid
This comprises wires placed in a pattern throughout the hull that capture electronic emissions and store them in capacitors. This grants DM-2 on any Technology (Sensors) checks to detect or lock onto the ship, and will stack with higher-TL Stealth coatings. Adding an Emissions Absorption Grid costs MCr 0.05 per ton of hull and consumes 2% of the total hull tonnage for the capacitors.

TL10 Stealth
This is a stealth coating that absorbs electromagnetic radiation (radar, lidar beams, visible light, etc) and disguises heat emissions, but is highly dependent on the Tech Level of the ship and that of enemies trying to find it. This gives DM-2 on any Technology (Sensors) checks made to detect or lock onto the ship, with an additional DM-1 for every Tech Level the ship is higher than the sensors trying to locate it. Stealth cannot be used at the same time as Reflec, but see Configurable Hull for a way to have both -- just not simultaneously). Adding Stealth costs MCr0.1 per ton of hull, and can only be added once.

Included for sake of completeness:

TL 10 Reflec
Reflec coating on a hull increases the  ship’s Protection against lasers by +3, but it cannot be used at the same time as Stealth. Adding Reflec costs MCr0.1 per ton of hull, and can only be added once.

TL10 Holographic Hull
Multiple holographic projectors are embedded within the hull allowing the ship to change hull colors, add graphics and adopt a different appearance (though its shape remains the same). Changing the hull color or adding a stored graphic can be done by anyone with access to the ship’s computer. Creating a complex color scheme from scratch requires the talents of a skilled artist.

Some young nobles try to outdo one another by changing the schemes daily or hiring artists to create the most complex scenes imaginable. Some pirates have made use of this system to simulate visual hull damage and lure other ships in with a GK distress call. However, most private ship owners use it for the purposes of advertising.

The military, however, makes extensive use of hull holography. During peacetime, the hull wears the bright colors and distinctive insignia of its fleet; during war, the hull blends in with the background to confuse visual sensors. This gives an additional -1 DM to detect the ship, but only against passive sensors, and is able to stack with both Stealth and Reflec as the projectors are embedded within, not on top of, the hull.

(Yes, you read that correctly: a hologram over a mirror doesn't stop the mirror from being reflective. Sure, pointing a laser at a ship with a hologram over reflec is still going to make the laser reflect off it, but now we're talking about the differences between active sensors and passive.)

A holographic hull system costs MCr 0.1 per ton of hull. The projectors are small enough that they do not consume tonnage themselves.

Also included for sake of completeness:

TL 12 Configurable Hull
This option allows a craft to switch between hull coatings. This is an outer-layer only change, and therefore it does not interfere with armor, the jump grid, or atmospheric integrity of the ship. It does not allow the addition of the same coating more than once. It costs MCr 0.1 per ton of hull, in addition to the coatings. It takes one turn, during the Ship Action phase, to switch hull configurations. 

GM ruling so I don't have to repeat it in every entry: regardless of TL, Stealth hull coatings do not and cannot stack DMs. 

Stealth also cannot be active as the same time as Reflec. 

TL12 Improved Stealth
Improved stealth enhances the traditional stealth coating by providing anti-masking measures through deployment of active emitter elements across all hull surface area. This protects against methods for detecting a ship by finding an absence or shadow in a sensor field.

Improved Stealth is a hull wrapping that contains millions of TL 12 3-D emitters, added underneath a specialized stealth coating that allows them to operate. They redirect and transmit multiple wavelengths EM radiation simultaneously from multiple viewing angles, allowing the vessel to transmit environmental EM signals “through” its space, manipulate its thermal signature, and ensure that it doesn't interrupt its background visual field.

This gives DM-4 on any Technology (Sensors) checks made to detect or lock onto the ship, with an additional DM-1 for every Tech Level the ship is higher than the sensors trying to locate it. Improved Stealth also has Holographic Hull as part of its suite.

Adding Improved Stealth costs MCr 1 per ton of hull and requires 1 ton of control hardware. It can only be added once. Improved Stealth requires the ship’s computer to run specialized software (Stealth Control/5) which comes bundled with the install.

TL14 Enhanced Stealth
As Improved Stealth, but the active emitters are blended with the stealth coating and the specialized control hardware is no longer needed, but more powerful software is required.

This gives DM-6 on any Technology (Sensors) checks made to detect or lock onto the ship, with an additional DM-1 for every Tech Level the ship is higher than the sensors trying to locate it. Enhanced Stealth also has Holographic Hull as part of its suite.

Adding Enhanced Stealth costs MCr 3 per ton of hull and can only be added once. Enhanced Stealth requires the ship’s computer to run specialized software (Stealth Control/10) which comes bundled with the install.

Summary of Results

• Emissions Absorbtion Grid gives Minor Stealth (-2 DM to detect). 
• Combines with Stealth Coating for Basic Stealth (-4 DM to detect, in line with 1e stealth).
• Holographic Hull gives an additional -1 DM to passive detection only, and is included in later stealth versions. 

• Improved Stealth Coating gives Improved Stealth (-4 DM by itself and -6 when combined with EAG. Also gives additional -1 DM against passive sensors per HoloHull).
• Enhanced Stealth is -6 DM by itself and -8 with EAG. Again, also has HoloHull.
• These last two are both ridiculously expensive and require computer bandwidth. 

I don't know how well these balance within a game session, but they look okay to my GM sense. I'll have to test them to be sure, however. and I welcome input from readers.