Detection

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Revision as of 05:20, 18 January 2014 by Foxwarrior (Talk | contribs) (That puts it at a base +4, easily. Maybe that's too many modifiers to pay attention to?)

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Stealth and Perception Circumstances

Various modifiers affect the Stealth of a creature relative to its observer:

Visual: Visual Perception is irrelevant for things for which you don't have line of sight to them or their reflection or shadow.

Partial Concealment: +2 Stealth. Shadows, mist, crowds, walls, and so on.
Distance: +1 Stealth for being 15m or more away, +2 Stealth instead for being 30m or more away, and another +1 Stealth for every 2 times that distance.

Auditory: Hear vibrations. It does not function in a vacuum. If there are obstructions in the way, auditory detection tells you only the first leg of the shortest path that passes through the minimum number of obstructions, and the total distance to the target.

Ambient Noise: +2 Stealth. Multiple conversations, machinery, and so on.
Distance: +1 Stealth for being 10m or more away, +2 Stealth instead for being 20m or more away, and another +1 Stealth for every 2 times that distance.
Obstruction: +2 Stealth. Sound-dampening walls.

Thermosympathetic: Thermosympathetic sense allows you to detect warm bodies and fires. Creatures do not normally possess a Thermosympathetic sense.

Undead: +2 Stealth.
Not On Fire: +4 Stealth.
Distance: +1 Stealth for being 15m or more away, +2 Stealth instead for being 30m or more away, and another +1 Stealth for every 2 times that distance.

Scent: Scent allows you to determine how far away aromatic things are to an accuracy of 1 meter. It does not tell you direction, although moving around to measure distance can allow you to triangulate.

Machine or Inorganic Object: +2 Stealth.
Not Afraid: +2 Stealth. Creatures currently suffering from a fear response can be detected more easily.
Not Wounded: +2 Stealth. Damaged creatures release additional chemicals into the air.
No Path: +6 Stealth. It's hard to smell the insides of wrapped boxes.
Other Strong Scents: +2 Stealth. It's hard to smell one thing when another thing stinks.
Upwind: +4 Stealth. If the wind is blowing scents of the target away from you, it's harder to smell them.
Distance: +1 Stealth for being 10m or more away, +2 Stealth instead for being 20m or more away, and another +1 Stealth for every 2 times that distance.

TEMPEST: TEMPEST is another form of stealth, only present in Cybergems. It can't be used to detect creatures or objects that contain no active electronics. If the TEMPEST perception beats the target's TEMPEST stealth by 4 or more, they can identify what active augments and electronic devices the target possesses, as well as what hacking they are currently doing.

Ambient Electronics: +2 Stealth. It's harder to pick out one signal if many other people have phones, lights, augments, and so on running in the area.
Distance: +1 Stealth for being 10m or more away, +2 Stealth for being 20m or more away, and another +1 Stealth for every 2 times that distance.
Power Spent: -1 Stealth for every Power spent since the previous round.

Any Sense: The following modifiers apply to all senses.

Heavy exertion: -2 Stealth while Running or jumping.
Attacking: -2 Stealth while attacking.
Attacking Target: -2 Stealth against the target you attack, while attacking.
Unrelated sensor: +2 Stealth against observers who are observing you through an intermediate medium, like a corpse mirror or a video feed.

Unconcealable Actions

Some things are essentially impossible to hide by their very nature, and have their own Stealth values.

Voices: When speaking, the speaker may choose a Stealth value of 0 or higher. The visual stealth for reading someone's lips is 2 points higher than the voice's auditory stealth.

Explosions: Things like exploding fire bombs, fireballs, and gunfire have an auditory Stealth of -1. If they do Heat damage, they also have a thermosympathetic Stealth of -1, and if they have an area of effect, they have a visual Stealth of -1.

Disguise

Disguises have a Stealth value: successfully Perceiving the disguise reveals that the disguise is fake. The time to create a disguise is equal to the listed time divided by your Items check. You can attempt to improve a disguise by accepting a penalty to your Items check: every -3 penalty adds +1 to its Stealth. If you accept a penalty and roll 0 or less, you cannot try to make that disguise again with a penalty that large for 1 week.

For every hour of wearing a disguise, roll two sneak checks: the disguise gets those bonuses to Stealth for the entire hour. It's possible, and sometimes necessary, to wear multiple disguises. When doing so, all disguises get the same hourly bonus.

Actually wearing the disguise and impersonating the creature involves bluff checks. For bluffs that aim to impersonate a specific individual or kind of official, the bluffer must have spent 5 hours studying such creature's mannerisms, or they get -4 to the bluff check.

Table: Disguise Stealths and Creation Times

Disguise Stealth Creation Time
Stolen Uniform Unlimited N/A
Stolen Uniform (Damaged) 4 N/A
Stolen Uniform (Repaired) 6 200 hours
Fake Uniform 5 400 hours
Conceal Identity as Stranger1 5 1 minute
Alter Facial Structure1 7 20 hours
Alter Skin Color1 5 4 hours
Increase Girth and/or Height1 (Clothed only) 6 (4 if more than +10% height) 4 hours
Conceal Body Parts1 (Clothed only) 5 1 hour
Fake Body Parts1 (Clothed only) 3 1 hour

1 Disguise must be crafted specifically for the creature wearing it.

Tracking

Creatures inevitably alter their surroundings in perceptible ways when they travel near solid objects, leaving heat, visible signs, and scents to mark their passing. The base Stealth of a creature's tracks is equal to the creature's Stealth +5.

Visual Tracking Modifiers:

Near Passing: +4 Stealth. If the creature doesn't touch anything, but passes within a distance equal to its Size, traces can still be seen. Any further, and no traces are perceptible.
Mutable Shape: -2 Stealth. If the surface itself can be crushed or shaped with gentle pressure, it leaves more visible tracks.
Decay: +1 Stealth per interval. Heavy rain for a minute, an hour of another creature traversing the same region, or gentle wind for a day, cause an interval of decay.

Scent Tracking Modifiers:

Still Air: -2 Stealth. If the air is still or a vacuum, scents remain longer.
Decay: +1 Stealth per interval. Heavy rain for a minute, gentle wind for an hour, or a day of another creature traversing the same region, cause an interval of decay.

Thermosympathetic Tracking Modifiers:

Near Passing: +2 Stealth. If the creature doesn't touch anything, but passes within a distance equal to its Size, traces can still be seen. Any further, and no traces are perceptible.
Decay: +1 Stealth per minute.

Tracking Teleportation: Teleportation leaves a very subtle telltale hum behind, with an Auditory Stealth equal to the creature's Stealth +2. The listener needs to beat the Stealth by an additional 1 to identify the distance teleported, or an additional 2 to determine where the creature teleported to.

Decay: The telltale hum gets +1 Stealth per round.