Combat Sense reduces the bonus to your enemy for actually 'Being surprised' from 2 to their benefit, to 1 to their benefit. Sixth Sense provides a 3pt benefit to Perception "to not be surprised". Where is this perception roll described? And I'm not using the Tactical Addendum, there's no tactical armor involved, no squads, no active sensors, just a dude with a stealth skill of 4-6 and the C$28,000 suit. So he's literally un-noticeable? People aren't that dumb. So, I wrote some of my own rules for stealth in personal combat, while also following the Actions chart, that says you only get a Perception skill bonus to your roll, if you spend a Basic action looking/paying attention. They also make good sense! A bit complicated, but I wrote up a sheet just for this so it flows rather easily. Even more easily than ranged combat.
Movement except crawling is a straight movement-type as per combat penalty to stealthed characters (walk is 1, run 2, sprint 3) with the additional penalty to the stealther of the 'target movement modifiers' (basically, exceed 10m, another -1), crawling is no penalty but speed modifier still applies (ahahah crawl 10...). Spotter is penalized for movement and also spotter's quantity of movement, if the stealther is prone/crawling they receive a straight ranged combat modifier for that, being 1pt penalty.
Spotter penalty for level of cover as per ranged combat, distance from potential spotter (not likely to be a factor, honestly...)
If the sneaking person is behind spotter they receive the 1pt benefit.
Stealther penalized for encumbrance/damage/fatigue as implied (it IS a skill check afterall). Spotter penalized identically, representing pain/exhaustion/inability to notice stimuli past being overladen.
Spotter given a bonus as if sneaker was a ranged target at their appropriate size.
To-spots are calculated roughly per turn, if the target ends up being beyond 12 then for the sake of brevity the perceiving characters do not get a check against the stealthed individual.
Basically at the beginning of each valid turn, the stealther "is shot at" by any Perceiving character exactly as if a ranged attack, but unless the spotter is actively looking and noticing (and thereby using Basic actions, for instance imagine a vigilant guard walking around actively noticing at things, would receive two notices per turn) the spotter does not receive their Perception score (now imagine a guard just kinda walking his beat half-staring at the ground pre-occupied - still has all his actions ... just not doing anything with them). Range increments are the Perception skill distances, compare equipment and target numbers as normal, skills, everything. It's just like combat!
To determine whether the sneaking person receives the bonus of "Target Surprised", if the sneaking character directly does anything that could warrant this bonus, the character about to be attacked (probably shot/stabbed/monowired in the head) is entitled to one free (no skill bonus unless they had been searching during the turn) perception roll in whatever state the map appears in immediately before the action, plus Sixth Sense if applies.
If the target succeeds at this 'last chance' perception roll, they are not surprised and all goes as otherwise, them detecting the sneaking character but the action still resolves, only minus the 1(combat sense)-2pt benefit to the attacker.
If the attack target fails to notice, melee notifies them immediately due to the nature of the attack (if they survive! Surprise heads-stabs are unbelievably lethal). If it is ranged, they receive another free perception check against their assailant, straight perception check (again, skill only applies if they were paying attention! Sentries be vigilant) along with all their various bonuses, and the addition of any suppression device into the equation as a penalty, but the attacker's skill, gear, and roll does not help them! It is simply a target-number attack, the only salvation that the attacker has is his ability to silence his gun. Also since it's simultaneous to actually being shot, the injury modifiers don't apply yet (they apply next turn, when he invariably searches for his attacker if struck)
So, if a character is going to shoot another from say five tiles away at short range for the weapon, stealthed character is wearing 2pts of equipment with a skill of 4, perceiving character hadn't been actively paying attention that turn (or lost initiative and hasn't had the chance yet, representing the stealthed character seizing a brief look-away and giving some sort of fair bonus to an initiative victory), victim character walking less than 10 and shooting character prone and immobile. No special cover or environmental conditions exist to help or hurt (medium grass for instance, not very-low-cut).
Stealthman: roll of 6, plus six for bonuses, unencumbered, from behind+1, no penalties. Score 13, success 5
Mook: Roll of 6, no perception skill, walking for -1, no perception mod (page 41, ONLY PLACE IT'S LISTED!?), no Sixth Sense, score 5, failure 2
Stealthman gets to shoot with surprise, called headshot with a Zeuss Heavy Rifle and attached JAF-05 he'd been laying on this whole time. Straight 2d6-7(target number), -5(head), +5(skill), +2(surprise), no range, +1(behind).
Roll 5, -7, -5, +5, +2, +1. MoS of 1. Target's weak spot attacked for massive damage (assume piercing, also target BOD of 6). Zeus does 5*2(head)=10 damage out of 12, target passes bleeding check, blah blah blah
Target now gets another perception check since there was a shot made, but it's a somewhat easier test, considering IT'S A GUNSHOT. Their attacker's overwhelming stealth ability doesn't play in, just them being prepared with a silenced rifle. 2d6-7(target)-4(silencer), roll of 6+6 explodes another 2, total success of 3.
Next turn with their appropriate injury modifiers, they get whatever perception check they might wish to make (presumably spending an action, to deliberately look for their shooter), and their detection of the shot gives them an additional 3 points bonus. Not likely enough to offset the penalty from a gaping hole in their head... but it's something.
If the attacker missed their shot (!? it happens), and the victim rolled the same, they'd still know a shot was fired because of a success (any failure means they don't even notice), and they'd also receive the aforementioned 3 points benefit to a perception check, even the passive one they receive for being in the presence of a stealthed individual.
How does that sound? Excuse me, I need an oxygen tank...
(and for the love of Blake, tell me if there's a simple definitive in-the-rules stealth section, because when left to my own devices with a problem like people sneaking around, I get elaborate, as you can see)
