(still in review: changes to be made include a section explaining Hiding and Silence statuses, and enumerating a variety of levels of them with corresponding resistances to being cancelled by other activity) 

The Stealth skill provides the character with a variety of techniques to conceal his/her presence from others nearby.  This includes the potential to both move about silently and hide so that nearby creatures may fail to see the character. 

In essence, these two activities, hiding and moving silently, represent the vast majority of the techniques under this skill, but there are a variety of limitations and special circumstances which should create a wide array of techniques to pursue.

Awareness Overview

The core mechanic for the Stealth skill is the Awareness status score, so we’ll need to go into a bit of detail on how that works.  Awareness and management of perception is intended to be a major subsystem of Voyages, and a distinguishing feature of the product/design: there are a lot of options and quite a bit of detail in many different activities, all tied to this value.

Every being in Voyages will have an Awareness status score, representing how alert that character is at that specific moment in time.  A variety of techniques will be potentially available for use to boost that score above the character’s “normal” value for periods of time.  Also, many activities will temporarily reduce the character’s Awareness when performed: if the character is busy examining a treasure chest, he’s less likely to notice the alligator drifting closer in the pond behind him.

Stealth techniques increase the base threshhold Awareness values needed to notice the stealthy character.  The base threshhold values of the character under normal circumstances are determined by apparel worn, lighting, and activities being performed.  These scores are modified for each observer, however, the modification determined by distance and intervening obstructions. 

There are both visual and audial threshholds to be considered, and there are two scores for each: a core detection value and a higher recognition value.  The detection value represents the minimum Awareness score an observer must achieve to realize the character is present.  The recognition value represents the minimum Awareness score required to have a chance to “recognize” the character: i.e. be told who they are and/or be able to memorize them to recognize the character if encountered again.

Determining whether an observer has detected another being or not is achieved by comparing the being’s threshhold values, modified for distance and obstructions, to the observer’s Awareness value multiplied by the appropriate Sense attribute score (Vision, Hearing, etc).  This procedure is a fairly common mechanic, and helps handle the impact of limited senses on observation situation.

Note that Stealth techniques are usually primarily focused on manipulating the character’s Detection threshholds, but will probably have a secondary impact on the Recognition threshholds as well.  Other skills, such as Disguise and Vocal Manipulation, include techniques far more focused on impacting the Recognition threshhold.

Stalking

Stalking techniques represent the wide range of methods of attempting to move quietly so as not to be detected audially.  There may be a visual component as well, but this is usually far less effective: motion is easily detected by nearly all creatures with any visual acuity whatsoever.

The results from a Stalking technique will usually be short-term adjustments to the detection threshholds of the character, especially the audial threshhold, and an allowed movement speed.  Speeding up beyond that movement rate will instantly cause the Stalking effect to drop.  Advanced Stalking techniques grant lower threshholds, faster movement, and lower corresponding costs in health/energy and status scores.

Hiding

Hiding techniques represent the variety of ways a character can try to conceal themselves visually.  There is usually a audial component as well to a hiding technique, and it is usually about as effective as the visual component, in vivid contrast to Stalking.

Hiding does have some fairly particular restrictions, however.  In essence, Hiding only acts to increase the lighting, distance and obstructed view modifications to detection attempts.  A character standing a well lit room, in full view, 10 feet away, doesn’t get much impact from the Hiding technique he’s using, no matter how skilled.  Also, a person using Hiding techniques cannot move, or the effect is lost.  Advanced Hiding techniques mean an ability to take advantage of lesser modification values, greater amplification of those modifier values, and lower costs in health/energy and status scores.

Stealth Techniques

It should be fairly simple to create a number of distinctive techniques for the Stealth skill.  There can be a variety of both Stalking and Hiding techniques, of course, covering various circumstances.  Stalking techniques can vary in their impact on movement speed, detection threshhold, and usage costs.  Hiding techniques can vary by having distinctive impacts on the three related modification factors (techniques that focus on low-light situations, techniques that focus on using obstructions effectively, etc.)

In addition, there could be techniques for monitoring the character’s detection threshholds, or for monitoring a target’s Awareness score.  Techniques allowing the character to evaluate a potential hiding place from afar might be appropriate, as well.  Adjustments related to mitigating the impact of armor and other apparel might also be appropriate (or perhaps those should be added to the Finesse skill, instead). 

Getting specific

Most of the Stealth techniques will be implemented as “adjustments”… the player directly activates the technique, which (assuming success) applies the corresponding effect to the character for a set period of time.  When the effect timer expires, if the technique is still activated, another skill check is made to either refresh the effect, or deactivate the technique (on failure).

As is typical with such “adjustments”, these techniques will take up at least one of the limited number of slots available on the character’s Concentration bar.  Deciding how best to manage the Concentration slots will be a large part of the decision making process in Voyages.

The only Stealth techniques I see at present that are “activities” as opposed to “adjustments” are the “evaluation” techniques: the “how am I doing”, “how alert is my foe”, and “how good is that hiding spot” techniques.   Given the fact that each of these will need to be used regularly to truly be effective, they should stand up fairly well as viable options for the player to pursue: in essence, they already are tied directly into the entire Stalking/Hiding process, so they don’t need to be a process in and of themselves.

Costs of Use

As mentioned previously, one of my “Rules” is that everything should have a cost.  Applying that to this situation is relatively straightforward.

The only obviously irrelevant status measure in relation to Stealth are the Readiness scores.  It is fairly easy to see how nearly all of these techniques should have costs in Balance, Stamina(physical energy), Sanity (mental energy/precision), Spirit (concentration/willpower), and/or Awareness.  Stalking techniques will likely impact Stamina and Sanity more often, while Hiding should probably hit Spirit most heavily.  The various evaluation techniques will need to have significant Awareness costs.

Specialization parameters

As with all skills, as the character progresses the number of techniques available will need to expand and specialize.  The Stealth skill is no exception, and we need a great deal more than just “Hide” or “Stalk”.

Specializations which focus on specific situations (low-light, obstructed views) are one possibility.  Trade-offs between different impacts (speed vs lower detection threshhold)  are another possibility.

Having some specializations which lean more heavily on Sanity as opposed to Spirit, or which impose higher Balance and Awareness costs in return for reduced health/energy costs, might also be a viable option.

Sample Technique

Basic Hide
Skill: Stealth
Related Attributes: Willpower, Size (inverted)
Complexity: 0
Base Costs: 25 units Spirit, 5 units Awareness
Minimums Required: none
Usage: fires once every 10 seconds once activated.  Cumulative “maintenance penalty” of 5 DAdv per consecutive firing applies.
Cooldown: 2 seconds

This technique alows the character to go into a basic Hiding state, reducing the chance of being noticed by other characters in the area.  The base visual detection threshhold value of the character remains the same, but the adjustments to that score due to lighting, distance, and obstructed view are all significantly increased, possibly as much as 50%-75%.  In addition, the audial detection threshhold increases as well.  This is an adjustment technique firing once every 10 seconds, and requires a Concentration slot.

(Be aware that this technique has no impact whatsoever upon any observer that has the character selected/targeted.)

(RF stands for Result Factor, which is the difference between the result of the Skill Check and the total required for success, typically 20000.)

Critical Success (RF 40000+): Improved Hiding status applied, adding 65 percent to all lighting, distance, and obstructed view/cover modifications.  Silent status applied, increasing base audial detection threshhold by 400+RF/100.  Any current “maintenance penalty” is eliminated.  Spirit cost is reduced to 20 units.  Cooldown is reduced to 1 second.  Each movement or physical activity halves the effect of the Improved Hiding status for the remaining duration, as well as immediately terminating the Silence status.

Special Success (RF 20000-39999): Hiding status applied, adding 50+RF/2000 percent to all lighting, distance, and obstructed view/cover modifications.  Silent status applied, increasing base audial detection threshhold by 200+RF/100.   No “maintenance penalty” increase in DAdv to next firing.  Any movement or physical activity terminates both status effects.

Success (RF 0-19999): Hiding status applied, adding 30+(RF/1000) percent to all lighting, distance, and obstructed view/cover modifications.  Silent status applied, increasing base audial detection threshhold by RF/100.  Any movement or physical activity terminates both status effects.

Failure (RF -1 to -20000): No effect.  Hiding status is deactivated immediately.  Technique is automatically deactivated after cooldown.

Special Failure (RF -20001 to -40000): No effect.  Hiding status is deactivated immediately.  Cooldown increases by 1 second per -5000 RF below -20000.  Additional Spirit cost (Depression/self-reproach) of 1 unit per -1000 RF below -20000 applies.  Technique is automatically deactivated after cooldown.

Critical Failure (RF -40001 and below): A Revealed (reverse of Hiding) status is applied, decreasing the base audial and visual threshholds of the character by 1 per -100 RF below -40000 (minimum of zero).  Cooldown increases to a full 10 seconds.  25 additional units of Spirit cost (Depression/self-reproach).  Technique and Revealed status are both automatically deactivated after cooldown.