yet another yet another stealth thread [Spellbound]

[merxa]

Like everyone else I'm writing a fantasy heartbreaker that's probably never going to be finished and never played, but hey, I'm having fun (sometimes). Basic mechanic is 3d6 vs DC. Advantage is to roll an additional d6 but take the highest 3 dice, disadvantage 4d6 take lowest 3. advantage / disadvantage stack and cancel each other out, ie with 3 sources of advantage and 1 disadvantage, you are left with 2 advantages, roll 5d6 take highest 3 dice.

I have a writeup for Stealth, and yeah, give me feedback please. The good news with being unfinished is that there is plenty of room to make changes, even major ones! I'll do what i can to make formatting nice looking here, but it's a low priority to the content.

Edit: I'll be editing the text below to incorporate changes and suggestions.
Edit: added system definition of (dis)advantage above
Edit: updated several sections, formatting has been largely lost as my primary document formatting doesn't convert to the forum.

Stealth
Use stealth to go undetected

During Combat
Stealth, Stealthing

Roll Thievery (Stealth)
Roll Thievery (Stealth). Stealth or Stealthing is an action which requires concealment, during which you move up to half your speed. If you end your turn without concealment, you are automatically detected and located (but moving out of concealment or between concealment during your turn does not automatically detect and locate you); similarly if you lose concealment outside of your turn you are automatically detected and located. Do not roll stealth more than once per round unless you attempt a second stealth action after a previous action negated your concealed status.

Anyone in your immediate area may make a perception (combat sense) check to detect and possibly locate you if they have not already rolled for the round. They roll perception (combat sense) check set at the DC of your stealth roll, plus or minus any relevant modifiers such as distance and if during the turn such modifiers like distance change the outcome, the one rolling perception (combat sense) succeeds at the moment the stealther enters the new square or the other modifiers becomes relevant. The opposite does not benefit the stealther -- you cannot turn a failed stealth check into success by increasing the distance modifier. The perceiver retains their perception (combat sense) check for the round and until the beginning of their next turn.

If you have not been previously detected, on the opponent’s successful perception (combat sense) roll they detect you, and if they succeed by 3 or more they also locate you. If you have been previously detected, the opponent locates you on a successful perception (combat sense) check.

If an opponent moves to a location where you can no longer reasonably benefit from the concealment used, you are automatically detected and located. For example, if within an empty T corridor, you move around the corner for concealment, and the opponent moves to the intersection, you are automatically detected and located. Alternatively, if the hallway is filled with tables, sofas, statues, it could constitute sufficient concealment. Another example, if hiding in the woods crouched behind a tree, an opponent decides to circle your location, the GM can reasonably rule there is enough intervening concealment sources from other trees and bushes to not warrant automatic detection and/or location. Alternatively, a single tree on an open plain is not likely to provide enough concealment if someone were to circle the tree.

Sidebar: do you know if you’ve been detected?
For simplicity and ease of play, during combat it is often better and faster to make all Stealth and Perception checks public and allow the PC to act on this information in a transparent manner, especially if the next action will be determining the outcome of an attack. However, especially against intelligent opponents, there may be times when it is more appropriate to keep this information private. Call for an opposed guile (bluff) vs either guile (sense motive) or perception (social sense) (roller’s choice), to determine if the character stealthing understands if a given opponent has detected or located them.

~~

Undetected
Others are not aware of your presence. They are considered flat-flooted to you. If you’re not in combat any overt action which could reasonably start combat triggers a surprise round during which you may perform the desired action. Some overt actions such as shouting may result in an automatic detection.

Detected
Others are aware of your presence, but not your exact location nor your exact nature, they believe there is ‘something’ nearby. Typically they know the distance category (close, medium, long, extreme, etc) and which hemisphere (which can be listed as north, east, south, west). In a hostile environment this often results in an initiative roll.

Once detected, you remain detected until the GM determines otherwise and this determination is largely contextual. For example, a creature may investigate, find nothing, and then continue their routine.

Located
Others know where you are, which spaces you occupy.

Concealment
Gaining concealment is contextual to the evident senses in play. For most demi-humans, concealment requires being not seen and not heard. The stealth roll represents how well a character achieves these goals, but a stealther must still benefit from some source or sources of concealment that obscures them from sight. In a stealth attempt you may move from an area of no concealment to an area of concealment. Depending on previous circumstances, you will remain detected if detected prior to this stealth attempt. A given terrain will be marked concealment, otherwise for additional circumstances, space can be marked as concealment as appropriate by the GM.

Leaving concealment does not necessarily make you evident immediately, but ending your turn without concealment does. Outside combat, in situations where sources of concealment are sparse or non-existent, remaining undetected could be functionality impossible unless you are able to cover distances between sources of concealment within one round.

Outside combat
Stealth should only be rolled when the character stealthing might be observed by something relevant. A character doesn’t necessarily know how well they are stealthing and it might be more appropriate for the GM to roll a character's stealth in secret. Unless stated otherwise, a stealth check should only be rolled once. To speed up play it is recommended to also have a character make a blind perception check, but circumstances and abilities may prescribe making additional perception checks with other modifiers while stealthing.

Typical uses of stealth outside combat might be to scout an area, infiltrate a location, shadow someone without them noticing, leave an area undetected, bypass a sentry or checkpoint. When in doubt, make opposed stealth vs perception (combat sense) checks with the perceiver winning ties. Two-eyed demihumans are assumed to have 180 degree peripheral vision and while there are no facing rules (and looking ‘behind’ yourself can be done in under a second), circumstances may dictate a given individual is not constantly looking over their shoulder or is largely facing a particular direction.

Sidebar blind rolls
Blind rolls are when someone rolls but does not know the outcome of the roll. Blind rolls can be useful to prevent players from acting on meta information as well as increase tension. Depending on how they are handled it can slow down play. You should always reveal the results of a blind roll after they are no longer relevant.

When scouting, roll a stealth check opposed by perception.

When infiltrating an area roll a stealth check opposed by a static DC

Activities, below are example activities associated with using stealth.

Shadow someone
Follow a target and keep tabs on their activities while they remain unaware. This is a separate activity from tracking someone, and depends on keeping the target in sight or near sight. Shadowing someone does not require a consistent source of concealment as you may not necessarily be hidden. When shadowing someone, declare a range category (typically close or medium). Some ranges may not be practically possible without special senses. Shadowing someone for longer is harder, as is shadowing someone in more deserted areas. Shadowing someone in the wilderness or in deserted ruins is impossible without a consistent source of concealment unless you can appear as innocuous and relevant to the local environs.

Scout the Area
Examine the perimeter, learn the extent of an area.
Characters scouting should also roll perception checks, and possibly other relevant checks. May discern weaknesses, obvious points of transgress, or other locations of interest.

Trespass
Enter onto property, allowing you to infiltrate the location. Often requires overcoming a physical barrier such as climbing a fence or opening a door. Some places are common areas and may not prohibit access, but remaining undetected could be difficult in crowded areas.

Surveille
Stake out important locations, track people coming and going. Learn more about the location. Surveillance can be more difficult over longer and longer time periods.

Infiltrate
Access sensitive areas. Sensitive areas will often have additional precautions such as locked doors, guarded entrances, traps.

Examples.

With ample concealment nearby, sneaking past…
A commoner: DC 12
2 commoners: DC 13
Small group(~4) of commoners: DC 15
Large group(~8) of commoners: DC 16
Multiple Large groups(20+), or high traffic Area: DC 18

Without unique and highly beneficial circumstances, larger groups or groups of groups cannot effectively work together to further increase the DC of a stealth check.

Increase the DC by the groups perception (combat sense) bonus, if uneven use the smallest bonus for the group. If members of the group are especially disparate, consider separating them into two or more groups and assign them each the appropriate DC. PCs and significant NPCs (sNPCs) should roll perception separately. DC assumes range of close (2 to 10 meters), otherwise apply the appropriate distance modifier based off of the closest the character must come during the sneak attempt.

Adjacent, within 1 meter, +1
Close, within 2-10 meters, +0
Medium, 11-30 meters, -1
Long, 31-100 meters, -2
Extreme, 101-300 meters, -3
Overland, 301-1000 meters, -4; 1001m-2000m -5, 2001m-3000m -6, 3001m-4000m -6, 4001m-5000m -7

Assign an additional -1 penalty for every 1000 meters beyond Overland. Without elevation, a medium sized creature cannot see anything beyond the horizon which is 5000 meters. See Perception for more information.

Perception Modifiers

do not consider an exhaustive list, See perception for a full write up. Apply additional circumstances as needed. If a circumstance makes you better or worse at a task apply a + or - 1, if circumstances make you more likely to do your best or worst, apply advantage or disadvantage. It is recommended PCs and significant NPCs roll if they are applying (dis)advantage, but if you need to assign a static DC then add + or - 1 for every net (dis)advantage. Keep in mind you can never roll above or below 18 or 3 no matter how many rolls or sources of (dis)advantage you are modeling in a given circumstance. So Multiple Large groups with multiple sources of advantage will still top out at a DC 19 stealth check before adding in the lowest common bonus of those groups.

Common Modifiers to perception DCs:
Distracted -1
Disorganized (apply only to groups) -1
Disinterested* -1
Commanding Location (eg, watch tower, crows nest), advantage

* If applying the disinterested modifier, if the steather rolls exactly the DC, consider having someone notice but not care or otherwise intervene.

Terrain modifiers to stealth

ignore if easily bypassed (such as with flight), add together all that apply.

Difficult terrain -1
Snow -1
Falling Snow (dampens sound) +1
Especially loud terrain (creaky floors, crunch leaves) -1
Howling Winds or other loud ambient noises. +1
Very Loud Ambient Noises (armies clashing, industrial machinery, operatic / orchestral performances) +2
Water (placid lakes, stagnant swamp, puddles) -1
Rushing water (river rapids, ocean wave breaks) +1

Misc

Invisible*, constant source of concealment (sight) and advantage on stealth checks
Magical flight, +1 and ignore most terrain
Mechanical flight, -1 and ignore most terrain
Magically Silent(self only**), +2


*You still displace matter around you, lose automatic concealment in water deeper than a puddle, see condition(invisible) for a full treatment.

**A distinction is made between the stealther able to magically silence themselves and their equipment, and an area of silence that causes all ambient noise in the area to drop to 0 decibels. Areas of silence are immediately evident to anyone inside one that can hear as all ambient noise and all noise created by themselves stop.

Modifiers for Shadowing, stack all that apply
Bustling market, +1
Carnival or extreme crowds, +2
Deserted or desolate area, -1
Inconspicuous appearance*, -1 to -3
Small village, -1
Hamlet, -2
Large city, +1
Metropolis, +2
Length of Shadowing**, -1 to -3

*The more you stick out from the locals, the more likely you will be noticed.
**GM discretion, typically for every hour apply an additional -1 up to -3, if the target is traveling large distances through town this time could be reduced between significant changes in venue.

Areas.
Sample Area Haskins Outpost
Perception (notice) DC 0
Visible from a few kilometers, a watch tower sits atop a local hill overlooking the surrounding fields and forested area.
1km?hex? Zone
Surveille. Every hour spent in surveillance increases stealth DCs by 1 up to a maximum of +3.

Stealth, Scout the Area DC 13; Success, identify the Watchtower.

Nature, Survival(track) DC 15; Identify Patrol Groups.
Perception, Search DC 15; Find Haskins Perch

Failure, chance of nearby patrol.
Critical failure, spotted by watchtower guard.

Haskins Events
16% 3-7 Patrol with Captain Notices you
34% 8-10 Patrol Notices you
34% 11-13 No Event
16% 14-18 Stumble upon Haskins Perch

Haskins Perch
A small brook runs through a clutch of berry trees and moss which provides a secluded spot with good sights of the tower and nearby area.

Surveilling from Haskins Perch does not increase stealth DCs.

Trespass DC 13 and 30m. The immediate area around the watchtower is bear of sources of concealment (besides being underneath the watchtower itself). You must be able to travel 30m in a single round while stealing to not be automatically seen by the two tower guards rotating around the deck.

Watchtower
A 10m wooden structure, climbed via a rope ladder the guards tend to keep deployed. A small 3m room, and 360 1m deck provides good views into the area.

2 guards per shift.

Infiltrate Watchtower DC 15
Success, Access the Watchtower’s small room.
Failure, Alert to presence.

[Kaelik]

Like everyone else I'm writing a fantasy heartbreaker that's probably never going to be finished and never played, but hey, I'm having fun (sometimes). Basic mechanic is 3d6 vs DC.

Jokes on you, people HAVE played Fiends and Fortresses once, and in response I had to rewrite two rules sections because people were so bored.

Concealment
Gaining concealment is contextual to the evident senses in play. For most demi-humans, concealment requires being not seen and not heard. A given terrain will be marked concealment, otherwise for additional circumstances, space can be marked as concealment as appropriate by the GM. Some source of concealment must block line of sense(sight) between the observer and stealther.

Since so much of your in combat stealth rules relies on concealment, and this section is so vague I'm really not sure what I'm dealing with at all. I think this could use a lot of fleshing out. For example, you say concealment means not being seen or heard, but then you say concealment is not having line of sight. Quite aside from not knowing how your line of sight rules work (IE, can you see someone who can't see you) I'm still not sure whether hearing matters or not! Do I need to be "unheard" BEFORE I can roll stealth, and if so, what counts as being unheard? Can I only roll stealth when something would prevent them from hearing my anyway, in which case it seems kind of pointless!

I THINK these rules make it impossible for anyone to ever sneak up on anyone and stab them, because as soon as you come out of cover you are automatically detected. I THINK they also prevent you from moving from one over to another. I think those are both bad things if they are prevented.

Outside combat

You may want to write these rules in more detail so it's not just designing each location as a table of events, or be specific that the idea is for all non combat stealthing to be a list of DCs and actions like this.

[merxa]

thanks for the responses! I should include a comma to better imply that the unplayed and unfinished descriptors were only meant to apply to myself.

I have a write up for perception, but it's rougher. Stealth rules can't really exist in a vacuum without perception rules.
~

The intention with concealment is to provide a framework for determining if its reasonable to have it or not, and to clarify that if someone has an unusual sense (like thoughtsense), they may detect someone even if they are invisible. Overall, I lean towards these abilities providing bonuses to a given creatures perception roll.

More generally, 'concealment' would likely be given out as PC abilities, ie 'Camouflage: you gain concealment in your favored terrain', so in some ways the rules here are written from the POV of a commoner, someone making due with only the terrain around them. I want to get the most basic of basics right before adding in the other fun stuff that makes it a fantasy game.

The goal is to clarify that the primary senses a demi-human uses is sight and hearing, that they may have other senses but they are unlikely to be relevant here. I do want to make a large distinction between in combat and out of combat. In the example of sneaking up behind someone and stabbing them, if this was outside of combat your initial roll vs the DC would determine if you are detected, then the surprise round would trigger, opposed stealth vs perception checks would be made then adjudicated. Whether you remain unseen and unheard is partly abstracted by the stealth roll itself -- but besides the abstraction of the roll handling that, I also want to make it clear if someone chooses to do something like scream or wear a bunch of tiny bells, that independent of the abstracted roll, they are producing evident sounds and the same would be for sight, that walking towards a guard staring down the other end of a long, empty, and well lit corridor will automatically see anyone not benefiting from concealment (such as from invisibility). The key for me that is doing the heavy lifting is, you only became evident if you end your turn without concealment.

So how long of a corridor can you potentially sneak down? Well, in combat terms, if you start your turn undetected, you can use the stealth action to make that opposed stealth roll, and move half your speed down that corridor -- and if that is enough to get you past the guard and around the corner before your turn ends then you remain undetected. Am i being clear here?

outside combat, the guard in the empty corridor might be mostly abstracted with a DC, but also might include a hard distance limit, and the stealther would need to be able to make that much ground in a single turn if they can't otherwise benefit from some other source of concealment. In the fiction this would read as someone timing their stealth while the guard is yawning and rubbing their eyes, or maybe they are fiddling with their greaves, reading a note, or just zoning out / snoozing for a moment.

How best to write this clearly to avoid obvious confusions? examples seem good to me -- perhaps examples under the concealment section?

[merxa]

I've expanded the section on concealment, and made some other minor changes.

Outside combat

You may want to write these rules in more detail so it's not just designing each location as a table of events, or be specific that the idea is for all non combat stealthing to be a list of DCs and actions like this.

I'm not exactly sure how to handle this suggestion, would a table of examples be helpful here? In general, the idea is to key areas with stealth DCs, but I do need to provide guardrails with DCs for common activities.

For me, writing stealth rules has two basic components. First and foremost is creating a functional procedure so people playing together can use stealth with a minimum of mind chalk. Second, is to successfully describe these procedures in text.

[Prak]

I get strong Skyrim vibes from this, but I'm not sure whether that's because it was actually any inspiration, or if that's just my reference point.

Overall, it seems workable. Maybe a bit complex, but way more workable than some kind of stealth points combat-esque thing that's been posited before. Honestly, I don't think the complexity is necessarily a bad thing, since when you're dealing with something like stealth, you do need to cover these kind of base terms and conditions.

[merxa]

I figured i’d just try to talk through how to develop a chart of example DCs in hopes it will help me actually generate one. So;

Stealth

Lets walk through common examples
~
DM: You all arrive outside a large, walled city. A line of caravans, merchants, farmers, travelers stretch out in front of the gate as guards inspect each visitor and collect a small fee for entrance. Something of an open air market has sprung up outside the gate, with plenty of people walking up and down buying and selling fresh food, linens, trinkets, as the guards seem to be in no hurry processing the line. A fine stagecoach with the heraldry of Duke Alamonx rushes by, breaking just enough stride to toss the guards a pouch of coin as it rolls through the gate.

Rogue PC: I sneak in!

DM: Sure, what’s your plan?
~
I think from here the space opens up in that limitless way which makes ttrpgs worth playing, but I’ll do what I can.

Example 1:

Rogue PC: You said there are plenty of caravans, could I attach myself underneath one?
~

At a base level, we’ll assume commoners are +0, they roll 3d6 which averages 10.5 and since stealth must beat perception (perception wins ties), the standard DC to sneak past a farmer working in the corn fields would be DC 12

In the scenario there are lots of commoners around, and we know if the DM were to roll 3d6 100 times some unlikely numbers will come out, 15, 16, maybe even an 18, a common pitfall in skill challenges -- ie if you have a 50% chance of success, but are asked to roll twice your odds dive to 25%.

Using 3d6, anydice tells us the highest of 3d6 and 3d6 shots up from 10.5 to 12.18, the highest of 3 sets hits 13.01, highest of 4 sets is 13.55, and the function I am using craps out at 5 (anydice will exit if it can’t calculate within 5 seconds).

Fortunately I can, I think, take the 3d6 probability distribution and use that to begin estimating how many rolls I’d need to hit that number 50% of the time. So getting at least a 14 on 3d6 happens 16.2% of the time… 1 - 0.162 = 0.838; 0.838^4 = 0.4931, so a little more than half the time rolling 3d6 in 4 sets I’m expected to get at least a 14 in one of those sets, that aligns with anydice’s 13.55 output.

Making calculations for 15, 16, 17, 18:

15: ~7 rolls
16: ~15 rolls
17: ~19 rolls
18: ~150 rolls

And just to round out the chart
10: 1 roll
11: 1 roll
12: between 1 to 2 rolls (highest of 2 rolls is 12.18)
13: ~3 rolls
14: ~4 rolls

Now, this is just tells us what to expect if we rigorously apply the current system and model, but this may not necessarily result in fun, and it may not even be especially ‘realistic’ in the sense that all these commoners waiting outside the gate can’t possibly pay attention to everyone else, and are all at different distances (under perception we will be applying a modifier based off range categories).

Instead, perhaps about 8 or 10 or so commoners are close enough to notice, our chart suggests they’d get about a 15, setting our DC 16. We may also want to apply a penalty, -1 for the commoners being distracted by the market atmosphere outside the gates, we could even consider applying another -1 penalty to represent disinterest -- just because someone say something doesn’t mean they’ll say anything, but there could be other ways to model the disinterest, so lets skip that.

So we end up with a DC of 15 to slip underneath a cart and wait for it to pass through the gates. If the DM wanted to apply the -1 disinterest modifier he could just take mental note that on a stealth check of 14 the PC, from their perspective still succeed, but perhaps soon a rumor spreads of people avoiding the gate toll by hiding underneath carts, and the poor city guards take on a halfling to do spot checks underneath future carts.

We are ruling that someone can go from being detected and located to undetected and unlocated once they gain concealment underneath the cart, and if that isn’t clear in the original write up it should be clarified. It could be better to say that the PC for the commoners in the area, doesn’t necessarily become undetected, several of them did just see the ROGUE PC a few moments ago, but now he’s gone, somewhere in the crowd perhaps. As for the guards, he was never really detected in the first place.

But let’s try to create a chart or summary so it’s actually usable.

When there is ample concealment nearby, sneaking past…
A commoner: DC 12
2 commoners: DC 13
3 commoners: DC 14
4 commoners: DC 15
7 commoners: DC 16
15 commoners: DC 17
19 commoners: DC 18
150 commoners: DC 19


Without some special setup, it’s a stretch to even think 15 people can effectively ‘take watch’ together upon the same visual horizon, so maybe we can abstract this into a couple easy categories

1 commoner: DC 12
2 commoners: DC 13
Small group: DC 15
Large group: DC 16

And then note, even in cases where say there’s an army of 10,000 that’s made camp at night, the perimeter guards is likely groups of 2 people, and there’ll be mostly small and large groups making meals between tents and campfires, perhaps in the center of the bivouac there are many guards and other attaches coming and going, so maybe the ‘19’ commoners category would become appropriate to use, upping the DC to 18, what to call this category? Multiple Large groups? High Traffic Area?

Finally, this chart is for commoners, who are +0, we might just make a note that if the group in question gets a bonus on perception (combat sense) to apply that bonus to the base DC, so if the typical town guard gets +1, while the elite elven rangers get +4, just apply that on top.

Other common modifiers could be:

Distracted -1
Disorganized -1
Disinterested* -1

But some of this might be better under the perception (combat sense rules), but since I don’t plan on using deadwood to ever publish this, I’m happying wasting cheap digital bits to create redundant sections in the ‘rulebook’

[JonSetanta]

Here's what I did with a 7 year old d20-like system

HIDING: STEALTH VERSUS SENSE

There are three degrees of hiding: Hidden, Found, and Targeted.
•Hidden: The character or group can not be targeted by an attack or Spell. They get a Surprise Round when initiating combat.
Each turn in which they take action against an enemy a Stealth roll is required. Otherwise, passively, Stealth + 10 is the TN required for a Sensing character to change the enemy to Found.
•Found: The character gives away their location by scuffing a foot or brushing up against something, motion is seen, or a faint odor is detected. The Sensing side knows the direction and distance of the Found character and can attempt to target them by attack or Spell with a TN 21 Sense check.
A further successful Sense roll against Stealth + 10 changes this to Targeted.
•Targeted: A Targeted character can regain Found status by seeking Concealment and attempting yet another Stealth + 10 versus Sense check. Otherwise, enemies can attack them normally.

[merxa]

Updated the original post to begin listing examples / guidance for common situations or modifiers.

Example 2

Let’s go back to our PC Rogue who has hidden underneath a cart, according to the rule set, they made a blind stealth check and we begin adjudicating it.

So they make their initial roll, and the DM, says ‘you slip underneath the wagon, no one around you seems to have noticed, or they don’t seem to care. You wait, and wait as the cart slowly moves forward in the stop and go traffic until you can hear the coarse voice voice: ‘How many are you, and what are you carrying? Its a silver a head and a gold per wheel.’ etc

Now for a small group of guards we have a DC of 16, compared to our prior DC of 15 to sneak underneath a cart without anyone making a fuss.

What if Shela, captain of the guard happens to be visiting? Again, we don’t want to roll for every NPC, but for NPCs that are ‘important’ or carry narrative weight, we want to give them some additional agency. As a demonstration, let’s reverse the situation, the PCs have been hired to act as toll guards -- above and beyond the PCs declaring how they go about this business, if they ultimately want to each be given a chance to succeed on perceiving any would be sneaks.

I would model PCs by giving each of them a blind perception check for the day’s activity, so the same should apply to important NPCs.

Mechanically, if Shela happens to be present, she makes an opposed roll at her appropriate modifier.

I think the caveat to apply here is that significant NPCs should be used sparingly, and you shouldn’t normally make use of more then one or two per scene -- and if you are using more then this should clearly be a group of nemesis, such as a rival adventuring group, a BBEG with their lieutenants, etc.

~
At this point, in my mind, there are still some unresolved issues for the stealth rule set. Group stealth checks and then unique abilities. Hopefully, I’ll take some time to work through these Sunday.

I also need to fill in more examples for shadowing (opposed roll, modifiers for circumstances), as well as the other categories listed. I also should go through the sample area provided and make sure it is consistently applying to the ruleset as it has been updated.

I was honestly hoping the den would be a little more excited by a proposed crunchy stealth rule set. I appreciate all the feedback so far, or people providing their own take on stealth. If people think there are fatal flaws, inconsistencies, ways to make verbiage clearer, i'm all ears!

Oh, advantage and disadvantage was not defined, I'll update the original document, but for each advantage roll an additional d6, but only take the highest 3, for disadvantage roll an aditional d6, take the lowest 3, (dis)advantages stack and cancel each other out, for having two sources of advantage would be 5d6 take highest 3, 2 sources of advantage and 1 source of disadvantage would be a net 1 source advantage (4d6 highest 3).

[merxa]

Group stealth, in some ways this is the reverse of group perception checks handled earlier -- just like having the rogue PC make the same DC 12 check over and over again until they inevitably fail, having the group of PCs make stealth checks individually, even if all the PCs are above average, it’s likely one of them fail. Add in the consideration you’ll likely have at least one PC be pretty bad at stealth, and the system preempts the group from even considering stealthing as a group forcing the rogue PC to go it alone or forgo one of their core specialities.

We can actually take in the inverse of the previous chart, when rolling sets of 3d6, and taking the lowest result, this estimates what half the time the lowest roll is likely to be:

9: between 1 to 2 rolls (lowest of 2 rolls is 8.82)
8: ~3 rolls
7: ~4 rolls
6: ~7 rolls
5: ~15 rolls
4: ~19 rolls
3: ~150 rolls

And perhaps this could be useful for NPC stealth rolls, but I rather encourage PCs stealth as a group. Since I already plan on adding perks as ranks in a skill increases, I can try letting those with larger ranks in stealth roll for others.

Stealth, perks
1 rank; when stealthing out of combat, you can assist one other target, who uses your check instead.
2 ranks; when stealthing out of combat, you can assist a small group (~3 others)
3 ranks; when stealthing out of combat you can assist a large group (~7 others)
4 ranks, when stealthing out of combat you can assist multiple groups (~20 others)

Group Stealth
When assisting others with a stealth check, roll stealth only once for everyone in the group. Apply any armor or size penalties members of the group might have. When there are multiple members, do not stack multiple penalties, instead apply only the worst penalty of a given type. Everyone in the group must still benefit from a source of concealment, some sources of concealment may not qualify if individual members of the group are too large to make use of it. Groups stealthing together are not assumed to be in very close proximity to one another, but may be stretched out along a distance across multiple sources of concealment. The group moves at the speed of the slowest member.

Note on ranks, I plan on using a 1 to 10 leveling system, capping max ranks to your level, so at level 2, max ranks would be 2 in a given skill.

[czernebog]

When characters are sneaking in a combat situation, how does your system handle the problem of needing to track the undetected/detected/located for (number of sneaking characters) × (number of perceiving characters) character-character interactions? The extreme example is something like a bunch of ninjas ambushing each other in a moonlit forest with clouds scudding across the moon and periodically plunging everything into darkness. There's a real potential for things to bog down if each other character makes a perception roll for each other character on every turn.

Relatedly, how does your action economy work, and how does it interact with the diminishing probabilities that arise from iterated rolls? Do characters automatically roll their perception against you every time it's their turn, every time you do something that might reveal you, or only when they choose to spend an action looking for you? If you're sneaking up on 10 kobolds in combat time, the odds are very good that at least one of them will hear you, and if those rolls are automatic then stealth falls apart like wet cardboard.

There are other potential pitfalls and desiderata in this old thread.

[merxa]

When characters are sneaking in a combat situation, how does your system handle the problem of needing to track the undetected/detected/located for (number of sneaking characters) × (number of perceiving characters) character-character interactions? The extreme example is something like a bunch of ninjas ambushing each other in a moonlit forest with clouds scudding across the moon and periodically plunging everything into darkness. There's a real potential for things to bog down if each other character makes a perception roll for each other character on every turn.

So I would be personally interested in knowing how you would take my write up and attempt to apply it to this situation -- mostly as an exercise in how clear the rules come across the page and where the confusions will occur.

But I'll attempt to answer it below -- if you want to engage in that exercise first then stop reading here.

Before I get to all the conditions, I'll just start with more basic examples and then layer atop the extra stuff. So the ninja's here are 'sneaking into a combat situation', let's suggest the combat timer hasn't started, in which case we will start with the out of combat rules. Let's continue with the moonlit forest -- there is plenty of concealment to go around, but let's take out the clouds causing periodic full darkness for now, we can come back to trying to simulate that later on.

If each of these ninja's are individual PCs then they would all make individual blind stealth checks, blind perception checks, and describe their actions until someone's perception check hit someone's stealth DC after applying relevant modifiers (such as for distance), then narrate who hears/see's what (unless the first contact beat the stealth DC by 3 or more then they would only get 'detected' and not located, but either way it would very likely trigger an initiative surprise either because the next declared action would be some sort of attack, or the character that detected something, 'a rustling noise a medium distance to the north' or 'unusual glint of light close to your east through the bushes', would move to investigate then locate the other ninja and then declare an attack which would trigger a surprise round.

Only those who had succeeded on their perception checks vs stealth DC would act in the surprise round, then we would begin combat time.

Before getting into combat time, let's make the situation a little more common, and say we have team Ninja PC, and team NInja NPC, I'll call these PNinjas and NNinjas. For NNinja's, they are lying in wait in the moonlit forest to ambush a rival team they have some reason to believe will be passing through these woods tonight. I wouldn't roll for NNinja's, instead i'd assign them a perception DC and stealth DC based off how many there are. Let's say it's a large group (8 NNinja's), applying the group chart for their size, they would be getting essentially a perception of 16+ninja bonus, and collectively a stealth of 6+Ninja Bonus -- but I'm going to assume the ninja's have at least 1 rank in stealth, that would let them roll stealth checks as groups of 2, so going by that chart above it would instead be about 4 rolls, so stealth of 7+ninja bonus, if they had 2 ranks they could do 2 group rolls which would be DC 9+ninja bonus, finally if one of 8 ninja's were a 'named' npc, maybe i'll apply the moniker of significant NPC or sNPC, master douj, if he had 3 ranks he could lead them has a full group and would only make one roll, for sNPC i'm inclinde to just give them a roll which would set the ambush groups stealth score (or the perception DC needed to detect them), otherwise it would be 11+master douj bonus. It should be noted that if they ended up breaking up into smaller groups I would adjust the perception DC to match, 4 groups of 2 would be perception of 13+ninja bonus, 2 groups of 4 would be 15+ninja bonus.

for team PNinja's, let's say there's 4 of them, they are sneaking through this moonlit forest to avoid the main roads, maybe or maybe not they are expecting an ambush, either way they would announce they are using stealth, anyone with ranks in stealth could loud a group action, PCs could make similar choices of individually rolling stealth, or being lead in a group, these would be blind rolls to avoid metagaming, and each PC would get a blind perception roll as well.

Ideally there would be some narrative descriptions of the forest terrain, perhaps here I would clue in the PCs of how pitch black it can become briefly as fast, low hanging clouds blot out the moon overhead. as a purely operational point, I might have a map prepared here, and let the PCs navigate through it, and if the PCs all rolled really bad perception checks but really good stealth checks, we could have a two ships passing in the night situation. But otherwise as perception distance modifiers decrease from extreme to long to medium to close, someone would detect someone else or both would detect each other, if team NNinja won the detection I'd declare initiative, likely starting with a surprise round. Any PCs with special abilities (cannot be surprised) would get to roll into the surprise round, but combat time would start. If the PCs detected the ambushers, I wouldn't necessarily declare initiative, but let the PCs tell me what they do, perhaps they double back and go around the ambush site.

Once combat time starts, in most cases beginning with a surprise round, and anyone who had rolled high enough to detect and/or locate the opposition would get to act -- in this situation the only time there wouldn't be a surprise round would be if everyone detected everyone else at the same time, an unlikely occurrence here, or if the PCs declare some action that forgoes stealth -- one of them shouts 'who goes there', or someone casts a spell with a verbal component. Now during combat time, we would roll initiatives, I use a vtt, so rolling 8 tokens onto the initiative tracker and having the vtt know which initiative belongs to which token isn't much of a burden, but I could also consider rolling a single group initiative for the ninja's or if they were 2 groups of 4 rolling two initiatives, if master douj was present he would always get a separate initiative roll.

During combat, anyone could continue to use stealth, even if they were detected and located, there is still plenty of concealment in the forest to go around, they would roll a stealth check and anyone nearby would roll opposed perception (as GM if I don't think this fight is especially important, I might only roll once for the group, especially if all have the same bonus, but more then likely i'd roll per token). These rolls would be public to speed up play, and I likely wouldn't immediately roll perception for all 8 ninja's until it became relevant because the person using stealth declares an attack, then I would roll against whomever is in the attack to determine their state, resolve the attack, the PC would then finish resolving any actions they had left, which might be another steath roll (I would have them roll again as attacking earlier broke their stealth), this last stealth check would be the stealth score until their next turn. Now if after PC1, PC2 goes and does the same thing, I would not repeat perception rolls, just use the ones earlier, or again, if they targeted the same nninja again use the original perception roll for that token.

Once nninja goes, if they hadn't rolled perception they would be entitled to take a free perception check anytime during their turn. Each additional perception checks after the first would cost an action.

Rinse and repeat, go to round 2, PC1 goes again, if they want to stealth again as their first action, I would make them roll again for the new round and begin adjudicating their actions. If their first action wasn't a stealth check but another attack I would let the previous stealth check ride and compare it as needed to the perception checks of the NPCs they target. They would be trying to beat the ongoing perception checks that everyone had already rolled. There is some metagaming here, where PCs will perhaps know a little more then then character, being sure to target the ninja's who failed their perception checks or deciding to start their new turn with a stealth action to try and bump up their previous rounds stealth so they can get the drop on a nninja they cannot get the drop on now. But I think keeping play moving here is more important then trying to stomp out this possible abuse, and if it did begin to feel very abusive I might start making the PC use blind checks again. If i wanted to increase the tension, and if master douj was present, perhaps I would make his stealth and perception rolls hidden, but this increased book keeping would be a balance call on the ability to continue keeping the round moving without the GM slowing it down.

So to summarize, in combat, people using stealth would have an assigned stealth DC from their stealth check, this would get refreshed every round, and everyone would have an ongoing perception check that determines which stealthers they can detect and locate (being sure to keep track of their last perception check as it would ride until the beginning of their next turn). In these scenario's each PC should know their perception check, and they, ideally, will be paying attention if I roll and NPCs stealth check to know if they are detecting/locating that NPC or at what distance they will locate them.

As for the moon getting covered by clouds causing complete darkness, I'd probably make some check in the beginning of the round (ie top of the round roll 1d6, on a 4,5,6 cloud cover causes darkness). It wouldn't otherwise impact the stealth game since in this scenario of the forest, I would suggest there is plenty of cover to go around. One mechanic I haven't flushed out is concealment distance -- in a very sparse wood of thin trees, it might be fair to say that concealment is available 10 meters from someone else, but within 10 meters there isn't enough concealment. If say this battle happened in an open field, or say someones attack clears the away concealment in a 30m cylinder, then maybe the cloud covered moon would one more provide concealment to everyone on the top of round it occurs.

Relatedly, how does your action economy work, and how does it interact with the diminishing probabilities that arise from iterated rolls? Do characters automatically roll their perception against you every time it's their turn, every time you do something that might reveal you, or only when they choose to spend an action looking for you? If you're sneaking up on 10 kobolds in combat time, the odds are very good that at least one of them will hear you, and if those rolls are automatic then stealth falls apart like wet cardboard.

I believe I largely answered these questions above, 10 kobolds would be a large group so the rogue PC would have a stealth DC of 16+kobold bonus. outside of combat it would just be that DC, and it wouldn't change any time soon. PC actions might modify their blind stealth roll. If this in a combat round then yes, I'm very likely rolling for them individually, unless this is a low-stakes combat (if these 10 kobolds are not a real threat to the PCs), then I'm more likely to just roll once for them so we can resolve combat faster.

I have not gone over my action economy yet -- but I can now. Everyone starts with 3AP (action points), and various actions cost different action points, stealth would be 1 AP, a single attack 1 AP, moving your base speed 1 AP (If you're stealthing you move at half speed, and 'stealth' comes with a move). Beyond that special actions, class features, spells, may cost more AP. I know action points is not a very popular decision on the den, but that's the current plan for the game system. I think with enough special actions costing different AP, it can become an interesting system. One example I will give is concentration -- I like 5e's spell concentration mechanic, but find it too limiting. Instead I can design a spell with a concentration upkeep of 1,2, or 3, so maybe a spell costs 2 AP to cast, and has an upkeep of 1 AP, that would mean that at the beginning of your next turn to maintain the spell you would spend 1 AP and start your turn with the spell up and 2 AP. I would be careful to essentially not provide any bonus AP, but maybe could provide virtual AP that applies to only very specific examples (ie 'mindless concentration', the first ap you would spend on upkeep to continue maintaining a spell is free). But all this first requires building an alpha of the system to playtest.

Surprise rounds would be a partial round, and I haven't fully determined this, but I am inclined to only hand out 1 AP during the surprise round. I'm not yet sure how I want to handle actions outside of a characters turn, either with the 5e 1 reaction per turn, or just key things that can trigger if they come up like attacks of opportunity.

There are other potential pitfalls and desiderata in this old thread.

past links to stealth discussions always welcome, I have read through a good amount of them prior, and have lurked here much longer then I've had an account, but it's always good to go back and review past concerns. Going through this exercise has caused me to add some revisions to the ruleset to ideally provide clarity. I'll try to update the first post with revisions soon.

[Lord Charlemagne]

Just read through the thread. I like what I read. I presume that Stealth is not the main focus of the game and is just an option the players can perform so things seem well enough in a usable order in a vacuum (Lots of little details can change when other parts of the system are factored in, such as detection magic for this example). The everyone is a ninja example is a pretty confusing read because of how thorough it is, but I think I get the general gist of it, albeit it does seem like a lot of die-rolling, but it seems like it would still be fine as long as the players are on board with how it will be handled & that there will be all that involved rolling each round if they want to have a ninja war campaign.

It was probably addressed in the post, but do all players roll perception against a single enemy stealthing against them out of combat or do they use the passive group DCs as well, meaning they do not roll perception & the enemy is the only one to roll stealth (functionally the same mechanically to how a player would stealth past a large or medium sized group of enemies)?

[merxa]

It was probably addressed in the post, but do all players roll perception against a single enemy stealthing against them out of combat or do they use the passive group DCs as well, meaning they do not roll perception & the enemy is the only one to roll stealth (functionally the same mechanically to how a player would stealth past a large or medium sized group of enemies)?

I am inclined to give PCs rolls because my default assumption is people like rolling dice. Typically a roll would be requested if a random encounter was generated during watch, or if players are engaging as sentries for a long period of time (in which case I might request blind perception rolls for a days guard duty, which might reset / be rolled again after any significant encounter that day, to try and mix up who gets first dibs on interacting with whatever they are rolling for).

albeit it does seem like a lot of die-rolling

if everyone is a ninja all the time, it's hard to avoid lots of rolls in combat, the main goal is to get it down to one roll per character per round (well, two rolls one for stealth and one for perception, but perception can be rolled on an as needed basis). More typically It'll be one or two PCs who want to use stealth in combat, so team monster will only be rolling perception if they are attacked to determine state, and possibly on their turn if they are looking for the rogue and haven't rolled already that round. And while many monsters might try to start combat off with stealth, only a few dedicated ones will be trying to use it every turn.

(Lots of little details can change when other parts of the system are factored in, such as detection magic for this example).

Yes, this opens up the question of handling special senses or other powers. 3.x stealth becomes an arms race of hard counters and hard counter-counters as rogues go up levels -- you can't airwalk? tremorsense detects you. Oh you can fly, do you have dark stalker or dampen presence? then blindsight sees you. Don't have mindblank or nondetection, then alignment sense detects you. There's no concealment nearby and the angel is radiating invisibility purge, oh you have hide in plain sight? What about lifesense, you got anything for that?

My inclination is to wrap all these abilities into making someone better at stealth or perception checks, my only problem with that is some monsters traditionally are not otherwise very perceptive like oozes. If i give blindsight a large bonus so oozes have a decent chance to detect things sneaking around, then suddenly something already good at perception with blindsight might be detecting someone hyper focused in stealth most of the time, and if blindsight a smaller bonus, it might not help oozes all that much, and maybe that's ok; but I like oozes and would like to see them in play.

I could cleave many of these senses into two categories, just as there is blindsense and blindsight, there could be lifesense and lifesight, and while a monster might have lifesense 30meters, lifesight might be more like 2m. But this might be the sort of compromise that makes everyone unhappy.

Of course since I control the design space, I can avoid handing out $TEXAS bonuses to stealth because someone used a second level spell slot or spent a few g's on shadow armor, so I might be overly concerned with dedicated stealthers escaping and then lapping the RNG before the game even hit its midpoint.

[deaddmwalking]

You can also give 'locating' an action cost. Ie, Tremorsense allows a creature to be 'detected' automatically, but locating them requires an action. Since it queues combat music, players can move out of the area (becoming undetected) or take another action to trick their opponent into 'investigating' another place. Oozes would be good at 'detecting' but not 'locating'.

[merxa]

Updated the first post to incorporate the discussion, added additional examples, modifiers, and tried to be slightly more repetitive in hopes that clarifies common questions.

You can also give 'locating' an action cost. Ie, Tremorsense allows a creature to be 'detected' automatically, but locating them requires an action.

This is a good suggestion, but I already have a detect / locate distinction that I am happy with. I am inclined to build out the special sense / special sight distinction, incorporating special stealth abilities that allows those using stealth to foil. A fuller writeup of that could make it clearer how viable that solution is.
~

I think I am going to move on to presenting perception next, likely starting a new thread. I may not continue to update the original post unless the core document is cleaned up significantly, or feedback causes major revisions. Thanks to everyone who provided feedback, as well as anyone who may provide some in the future.