Topic: Todays' Discussion: Invisibility

[Luxferre]

Hey!

We are playing RMFR in a homebrewn low-magic world.
So our DM has some extra rules for the use of magic, like special tables for failiures ... so you may catch the attention of benign beings and so on ..
(so far for the premise)

How do you all handle "Invisibility" and spells the like?
Have you houseruled anything?
How can these spells be restricted any further, than being naked? How can "offense actions" be specified?

In our (yes, we all agree at the table) opinion, "Invisibility" is very powerful in the hands of a creative player.

Let me know your thoughts, ideas and opinions on that spell ... and how to handle in low-magic worlds.

P.S.: i will be the only spellcaster in the group, a priest of darkness and night (channeling companion) and we want to skip the two lists "communal ways" and "summons" for two other lists, that fit into the homebrew background. (not to be discussed here  )

[jdale]

Any type F spell (i.e., spells that give the target a RR) or elemental attack spell also breaks invisibility. (That's explicit in RMU, but not discussed in RMSS.) Aside from that, pay attention to the rules about detection (invisibility isn't perfect) and also note that some creatures have senses that limit its effectiveness (e.g., dogs may still smell you, and demons have otherworldly vision).

[MisterK]

I did not house-ruled anything about invisibility because I didn't need to.

Invisible people can still be detected by non-visual means. They are vulnerable to AoE effects. Dispel works on invisibility. Even the old-fashioned flour cloud works wonder (and rain produces a wonderful fringe effect).

If you add to that the fact that an invisible person who performs an offensive action [any action that would trigger an active or passive defence in the target - physical attack, elemental attack spell, any spell that triggers a RR...] becomes visible, I didn't need to tone it down. It is useful for approach and infiltration for people who are already fairly good at such activities, and provide an element of surprise if the opposing force does not include people who are expecting invisible opponents. I actually had the whole group perform first strikes while under flight, invisibility, and silence. The players loved it because they got the feeling of being powerful. They also knew that they could not do it against elite opposition, because it would be detected and would trigger counter measures.

The mentalism version, however, can be scary in the right context. I had an Enchanter in my last group, and he thankfully agreed to tone the class down a bit.

[rdanhenry]

Any type F spell (i.e., spells that give the target a RR) or elemental attack spell also breaks invisibility. (That's explicit in RMU, but not discussed in RMSS.) Aside from that, pay attention to the rules about detection (invisibility isn't perfect) and also note that some creatures have senses that limit its effectiveness (e.g., dogs may still smell you, and demons have otherworldly vision).

And human being have ears. And anything you disturb is just as visible as if you were. Honestly, invisibility is an ability of rather limited usefulness. You need open space, a solid surface, and you often still need to be stealthy (now, if you can collapse off the side of a battlefield in what happens to be a safe spot, huzzah, you survive, but you aren't being exactly useful).

Invisibility somewhat reduces your chances of being caught sneaking around, but it also ensures that you aren't going to be able to talk your way out of it. You definitely weren't "just lost", you were sneaking around.

[JakeM.]

Any type F spell (i.e., spells that give the target a RR) or elemental attack spell also breaks invisibility. (That's explicit in RMU, but not discussed in RMSS.) Aside from that, pay attention to the rules about detection (invisibility isn't perfect) and also note that some creatures have senses that limit its effectiveness (e.g., dogs may still smell you, and demons have otherworldly vision).

And anything you disturb is just as visible as if you were. You need open space, a solid surface, and you often still need to be stealthy.

Invisibility somewhat reduces your chances of being caught sneaking around.

While I agree mostly I have few point.

Normal guards, sentries, etc rely on their eyesight as first and foremost way.
Ears yes but only in otherwise dead silent surroundings, the more backround noise the more irrelevant ears become.
Of course in high fantasy settings some places are magically guarded and thats on altogether different thing.
But if you walk invisible thru some grassy field during a windy day one has to be pretty excellent observer to see grass blades bending under your feet.


Side note: I’d love to see some quality cgi rendering of something invisible wade thought a thigh deep water 🧐👍

[chook]

Appendix 9.17 on page 204 of RMFRP (5800) has great information relating directly to this.

[pastaav]

Normal guards, sentries, etc rely on their eyesight as first and foremost way.
Ears yes but only in otherwise dead silent surroundings, the more backround noise the more irrelevant ears become.

Assuming that training for regular guards does not include how to deal with invisibility spells is kind of a stretch. In a fantasy setting, there is invisibility and mind control and the person training the guards has very good reasons to make sure the guards can perform their duty.

High-security places will employ magic to increase the level of security but in my game, even regular guards will know the tricks. Having a sack of flour available for occasions when the guards suspect invisible intruders costs a lot less than having the guards fail to repel an intruder that will steal your valuables.

[Luxferre]

Thanks a lot for all your input 

We can work with that as a base for adjusting the spell a bit.
I will talk tot our GM and will give feedback, how we handle it.

[Jengada]

This just gave me an idea for a room set-up. As noted, in a world where invisibility is a possibility, guards and security people will take some level of precaution. So a treasure vault or similarly high importance space could have magical countermeasures, but it could also have mundane defenses. Something as simple as a trip-wire that releases a gentle rain of flour or dust, making invisible foes visible, would work.
Honestly, I like the idea of a party that doesn't have any invisibility wandering into this space. They would wonder why dust is suddenly falling on them - is it poison? Drugs? Or it might just confuse them.

[MisterK]

The problem is more when you have to monitor an area that is actually used by people - you have to be more forceful in the monitoring in this case, because you have to catch the invisible people without making life too difficult for authorised persons, and, whenever possible, without authorised persons knowing that there is an active monitoring and what form it takes. Any counter-measure that requires specific actions by authorised people in order to avoid them will be noticed (and even worse, the "authorised people" might talk). Even a comprehensive search by guards might be considered offensive by visiting persons of importance. And if guards cannot do their job properly, then you have a potential weakness.

Which means that selective magical detection is still the best compromise, until someone performs spell analysis locally and determines what the monitoring does - at which point designing a countermeasure becomes much easier.

In short - the most important factor in deciding whether an intrusion gets through or not is usually knowledge. Intruders who do not do their homework are likely to get caught. Intruders who do likely won't. Thus, any intrusion is typically resolved by intelligence and counter-intelligence.

[rdanhenry]

Areas used by people are the worst areas to be invisible in. The more crowded it gets, the more difficult it is to avoid contact with people who won't be avoiding you, because they can't see you. And while the contact itself might not break the invisibility, most people are usually going to notice when they bump into something that "isn't there".

[MisterK]

Areas used by people are the worst areas to be invisible in. The more crowded it gets, the more difficult it is to avoid contact with people who won't be avoiding you, because they can't see you. And while the contact itself might not break the invisibility, most people are usually going to notice when they bump into something that "isn't there".

You're thinking about a crowded street. I'm thinking about an office building. Not that many people, and they move in fairly predictable ways, but they *use* the place, so you cannot simply set traps wherever you would like.
Plus, following someone is often a good way to foil at least some monitoring measures.

[pastaav]

You're thinking about a crowded street. I'm thinking about an office building. Not that many people, and they move in fairly predictable ways, but they *use* the place, so you cannot simply set traps wherever you would like.
Plus, following someone is often a good way to foil at least some monitoring measures.

Sounds like evil overlords making ventilation shafts wide enough to hide intruders. If security is a serious concern you will design the entrance to office space so only one person can use it at the time. You force the crowded situation and make it is easy for the guards to monitor if the opening is being used by gates that need to physically opened to let the person past. In cases when something larger need to be transported you must open a wider opening and have special security protocols for the guards to follow.

Also lethal traps cannot work in a everyday place but such is needed if there are guards at the checkpoint. Having traps that trigger if two persons try to move past the checkpoint and notice the guard would not be a deal breaker for everyday use but a serious obstacle for the intruder. It is obvious there is always way to use magic to defeat mundane defenses if you have researched the layout of the defenses, but some magic protection to aid mostly mundane counter measures is much more reasonable than relying totally on magic and having entrances designed like in our world when there is no invisibility.

[MisterK]

Oh, I readily concede that, if you want to go all-out, you can have security tight enough that only a major effort will breach it.

And it comes at a price. Two prices, actually : the need for absolute secrecy, and the maintenance cost.

In order to have that kind of security, you also need to remove the human weakness factor from it. Which means ensuring any security personnel cannot fail (using, say, mental influence), and cannot talk (even involuntarily). That, plus the actual material and magical maintenance of the security system, makes it a very costly proposition, especially over long periods where you have to keep the human factor motivated at all times. There are countless examples of how that turns out.

The alternative is to switch to non-living security (constructs or undead) to remove the human weakness factor. And that increases the cost even more (up front, and maintenance as well).

The problem is, spending is always a trade-off, even if you have boatloads of resources. The more you spend in one place, the less you spend elsewhere, and the more prone to intrusion those other places become.

If you add to that the variety of options people have in RM magic to breach protections, protecting against everything becomes prohibitively expensive and constraining. The most likely outcome is apparent deterrence : you make your security measures appear more grandiose than they actually are to preventively fend off would-be intruders. It won't guarantee safety against truly determined intrusion, but it will hinder it and make it more risky, and *will* deter the less motivated ones. It's a cost-effective approach for things you cannot hide.

The last, and possibly most cost-effective security measure is the "needle in the hay" method : you hide in plain sight, and drown the would-be thief in false signals. If everything registers as magical, how can the thief make a quick decision ? If there are tens of thousands similar-looking documents, how can they find the relevant one quickly ? Once again, it's no guarantee, but it will likely take the thief more time to sort through the fake positives than they can comfortably afford before they are noticed and have to retreat.

Once again, the overwhelming preventive countermeasures do work. They are simply not practical when there are alternatives that work better on human psychology : make everything appear tougher than it actually is, ensure that no one knows everything, remove regular patterns, take into account a potential successful intrusion and make them spend more time than they have, and actively misdirect by seeding false information about what is valuable and where it is stored.

After all, if the intruder steals a fake document that is magically marked so it can be traced, you have lost nothing, you might have gained useful information on how the defences were breached, and you certainly can use the marked document to remove those pesky intruders and make an example of them.

Because in the end, where is the fun in an impregnable defence when your PCs are those who want to breach it ? As a GM, I am playing with and for my players, certainly not against them. The only point of having something difficult to access is to make an interesting story out of eventually getting it.

[jdale]

I don't think absolute secrecy is needed. For example if the security is that everyone entering must pass through this door and this corridor, and a magical bell dings as each person passes, the guard doesn't need to know exactly how the bell is made to ding, and anyone passing through is going to be aware of the layout anyway. The guard also doesn't need to know that there is a second trap that slaps anyone protected by invisibility (with an illusionary strike triggered by a detection effect, in order to break the invisibility). The guard can talk about the security procedures but that doesn't undermine the security in any real way. (Especially if the bell and a person monitoring the bell are out of line of sight for people entering.)

[MisterK]

I don't think absolute secrecy is needed. For example if the security is that everyone entering must pass through this door and this corridor, and a magical bell dings as each person passes, the guard doesn't need to know exactly how the bell is made to ding, and anyone passing through is going to be aware of the layout anyway. The guard also doesn't need to know that there is a second trap that slaps anyone protected by invisibility (with an illusionary strike triggered by a detection effect, in order to break the invisibility). The guard can talk about the security procedures but that doesn't undermine the security in any real way. (Especially if the bell and a person monitoring the bell are out of line of sight for people entering.)

Actually, it still undermines security : knowing that a bell chimes as each person passes allows to come up with alternatives, such as not passing (e.g. long door), or using silence to ensure that, even if the bell chimes, no one will hear it. It also provides the information that there *is* a person assigned to monitoring the bell, and thus a potential single failure point if you know which guard is on bell duty at a precise time (a guard can be bought, convinced, blackmailed, or controlled). You can also make them doubt the reliability of the mechanism by triggering false alarms and wait until either the guards don't trust the system any more or people come to 'check' the system (and likely bring it down temporarily).

Knowing about security means that, instead of going head on, the infiltrators are going to work around the security measures they know about, and try to learn more about them - not to mention try to learn more about the people who operate those security systems.

As most people who work in security know, the weak link in a security system is often the people who work in the place and how they can reveal sensitive information or carry trojan horses unknowingly.