Alternative sensors rules

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Alternative sensors rules

Postby Boldtaar » Wed Jul 18, 2018 7:23 pm

I have created a new system for setting difficulty for sensors checks based on what sensor details the ship can pickup.
Why you asked?
Because the core rulebook don't come close to what I need when I play. There is no rules for deterring at what distance a ship is detected by sensors and setting different difficulty baste on range, ships size and tactics.

(This is still a work in progress!)

Take the best Senor detail from available for sensors on the ship according to the Range on the Sensor Target table on page 150 in the core rulebook .
Sensor check difficulty based on best Sensor detail:
Full: DM +-0
Limited: DM -4
Minimal: DM -6

For every extra senor that have the same Senor detail DM +2
For every extra senor with lower Senor detail DM +1

Target on Long range gives the following Sensor details in to the core rulebook.
Visual: Limited
Thermal: Limited
EM: Minimal
Active radar: Minimal
Passive radar: None
NAS: None
Densiomter: None

A ship with Civilian grade or Improved sensor has Visual, Thermal, EM and active/passive radar (according to how I interpret the rulebook).
The best Sensor detail for the ship is Thermal: Limited, that gives a Sensors DM -4
The ship also have Minimal Senor detail for EM and Minimal Senor detail if using if they using a Active radar and not passive. This is lower then the EM detail there for only gives a DM +1 for each of the other two sensors.
I don't count Visual senor for DM if the Traveller isn't suspicious and looking/scanning specifically in the general direction of the Target.
In total that gives a DM -2 (-4 +1 +1) for senor details available.

Long range scan
The total DM fore a ship with Civilian grade senor is DM -4 (-2 for sensor detail and -2 for sensor type)
The total DM fore a ship with Improved senor is DM -1 (-2 for sensor detail and +1 for sensor type)
I'm also considering giving Travellers a Boon for using Active radar. (Enemy still get DM +2 to detected Travellers in return) but not played test it.

If the distant had been Close
The total DM fore a ship with Civilian grade senor is DM +2 (+4 for sensor detail and -2 for sensor type)
The total DM fore a ship with Improved senor is DM +3 (+2 for sensor detail and +1 for sensor type)

If the Travellers use stealth tactics like shunting down ship systems and engines or hiding on behind a asteroid to minimizing EM signature or radar signature then the Sensor detail for the effected sensor is moved one or several levels lower.
Same thing can be down using tech ship upgrades. Butt haven't done any detail rules for this yet.
I also add DM for size of target ship, a fighter should be harder to detect the a capital size ship. But have't set numbers on tonnage yet.

What do you think?
Lost Space Viking. I'm a new to Traveller. Please don't space me!
All rule reference is to 2nd edition, if not otherwise mentioned.
Lesser Spotted Mongoose
Posts: 725
Joined: Tue Oct 01, 2013 6:13 am
Location: near Seattle

Re: Alternative sensors rules

Postby steve98052 » Wed Jul 18, 2018 8:11 pm

An interesting consequence of the immense radiation resistance of a basic starship hull is that it should be able to keep a whole lot of radiation from escaping, not just keep inbound radiation from reaching the ship's interior. That could greatly reduce a ship's radiation signature for direct radiation; most radiation from a ship might be from radioactive materials vented to space. So if a ship wants to be stealthy, just switch the power plant to whatever setting that is used in planetary atmosphere to avoid dumping fallout.
Cosmic Mongoose
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Joined: Sun Dec 13, 2009 6:13 pm

Re: Alternative sensors rules

Postby ShawnDriscoll » Wed Jul 18, 2018 8:32 pm

Boldtaar wrote:
Wed Jul 18, 2018 7:23 pm
What do you think?
The beauty of Mongoose Traveller 2nd edition is the culling of DMs from Task Checks. They should be used sparingly. What does the Vehicle Handbook say about advanced sensor rules that the Core Rulebook suggests using?

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