Sneaky Spellcasting - Casting in Public, Casting while Hidden

[Greywander]

I'm going to be playing a shadow monk / rogue in an upcoming game and I get a free pick cantrip from my race. I was looking over my options getting frustrated at how many of them would be good for doing things while sneaking around except for the fact that they have verbal or somatic components (but especially verbal). RAW, there are no rules on how noticeable spell components are, which only makes it worse. I know that if I'm standing right in front of someone while they're watching me they'll definitely notice that I just cast a spell. But what if I'm 30 feet away, in the bushes, while their back is turned? I joked that it would be canon in this campaign that verbal and somatic components would just be shouting "Shazam!" and striking a Jojo pose, but I'd actually like to see if I can come up with some sensible rules for this.

Now, the sorcerer does have the Subtle Spell metamagic, and I don't want to make that completely useless. That said, we do have a precedent with the Disarming Attack Battle Master maneuver and the Disarm action. The maneuver is only available to those with that specific feature, but it is more powerful in what it does. I think we can find a happy middle ground that does something similar with Subtle Spell and other casters trying to cast on the sly.

First thing's first, Subtle Spell completely bypasses verbal and somatic components. If you're unable to speak clearly or move your hands, you need Subtle Spell to cast a spell with those components. Subtle Spell also just works, no ability check required, no chance at failing. There are also no limitations or requirements; you can use Subtle Spell 100% of the time you cast a spell.

I want to split this into two parts: casting in public, and casting while hidden. You cannot do both at the same time, except with Subtle Spell. Verbal and somatic components will also be treated separately for each of these cases.

Casting in Public

Casting in public assumes that you'll be drawing attention towards yourself, and so it makes no effort to try and conceal the spell components. Instead, casting in public tries to mask those components by incorporating them into other dramatic displays. You might start speaking in a singsong voice with slurred words, only to chain into an incantation in an arcane tongue with a similar singsong quality, and back into meaningless gibberish at the end. Magical hand signs might be mixed with dramatic gestures that have no meaning.

Methods for sneakily casting in public are even more dramatic than standard spell components, and will reveal you if you are hidden. Also, they can draw unwanted attention and make you look suspicious, potentially putting a disguise or false identity at risk.

For verbal components, make a Charisma (Deception) check. For somatic components, make a Dexterity (Performance) check. This is contested by other creatures with an Intelligence (Arcana) or Wisdom (Insight) (creature's choice). Those who beat you in the contested check see through the guise and can tell that you've cast a spell.

Casting while Hidden

Casting while hidden does the opposite of casting in public. Verbal components are recited quietly but clearly, and somatic components are performed slowly and precisely. To anyone observing you, it is immediately obvious that you've cast a spell. However, casting while hidden assumes you aren't being observed and would like to keep it that way.

To perform verbal components while hidden, there must be some ambient noise to mask the sounds of the components. Even then, anyone standing close enough to you will be able to hear you automatically. A creature will automatically hear you if within 15 feet (quiet ambient noise), 5 feet (loud ambient noise), or won't hear you automatically even when right next to you (very loud ambient noise). Concealing verbal components uses a Charisma (Stealth) check. Roll with advantage if there is very loud ambient noise. You cannot conceal verbal component if your surroundings are totally silent.
Ambient noise examples:
Quiet. The chirping of crickets, the rustling of a light wind, a hushed conversation in a nearby room, a carriage rolling on a well-kept road, calm ocean waves.
Loud. Light machinery such as a windmill, the rustling of a heavy wind, a conversation in the same room, a busy road, a waterfall.
Very Loud. Heavy machinery such as a combustion engine, a raging storm, many conversations in the same room, a marketplace, a boisterous festival.

To perform somatic components while hidden you must be either (a) lightly obscured, (b) at least 100 feet away, or (c) that creature must be facing away from you. Make a Dexterity (Sleight of Hand) check. If you are behind total cover, invisible, or otherwise unable to be seen, it isn't necessary to conceal somatic components.

In either case, if you roll less than your current Stealth check, this roll replaces your Stealth check for the duration of the spell's casting time, after which you revert to using your previous roll for Stealth. If you conceal both verbal and somatic components, use the lower of the two rolls. If anyone notices you, they can immediately tell that you are casting a spell.

Casting while Hidden in Public

I know I said you can't do both, but this is really just using the Casting while Hidden rules, but with you blending in with a crowd instead of hiding. 5e doesn't really have rules for blending into a crowd, so I suggest using a Charisma (Stealth) check. You might require that the character have nothing distinctive about their appearance (e.g. being the only one wearing armor or carrying a weapon, being an exotic race, wearing a uniform or costume different from those around you), similar to how the Hide action requires you to be heavily obscured. The more varied the people around you, the less you have to worry about having a distinctive appearance. It is much easier to blend in with a crowd milling around the marketplace than it is to blend in with a military squad in uniform marching in step.

Things like security checkpoints (like at the airport) are specifically designed to filter crowds in such a way that each individual can be examined, making it impossible to stay blended in with the crowd. Blending in relies on not giving people a reason to pay attention to you, so if they already have a reason to do so then the only thing you can do is hope they don't spot you in a crowd. This is where they would make a Perception check against your earlier Stealth check. If you're singled out at something like a security checkpoint, your stealth is broken in the same way as if you stepped in front of a guard rather than sneaking past them.

Once you've hidden in a crowd, just use the normal Casting while Hidden rules. Since this necessarily means you'll be around people, you'll need to be extra careful regarding what direction people are facing, how much ambient noise there is, and how close you are to other people. Keep in mind that other creatures can provide cover for you, making it easier to conceal somatic components from a room full of people. It's also fine to use passive scores instead of rolling for each creature to see if they detect you.

What do you think? Does this framework seem solid? Any numbers you'd change? Would you use different skills or ability scores? What about the limitations?

[MrStabby]

I think I would err on the restrictive side.

Subtle spell is one of the sorcerer's better features. The gap, in terms of real things that actually happen at the table and make an actual difference to gameplay, must be big enouh that the sorcerer is happy to be a sorcerer and to take this as one of their abilities.

Secondly, there are spells without verbal components. You likewise want to be fair to those that opt into these; the average power between a verbal spell and one not needing such components should be small, and if providing any means to be stealthy opens up a gap between them and means that selecting the verbal component spells is now better, then this is poor balance.

Thirdly, there is the balance point between casters and martials. A silent blade in the dark is very much a martial strongpoint and if you let casters close the gap with martials on effective stealth moves, then that's pretty bad.

None of these are hard and obviously depend on the campaign. If casters are tightly nerfed due to enemies and availability of anti-magic whatever then loosening up a bit is fine.

Likewise, if the sorcerer is super-powerful in the campaign setting for one reason or another and is blowing away the bard and wizard in power levels, then letting other classes step into their space is less bad.

Or maybe you are running an underwater adventure where there will be unexpected underwater combats (unexpected so water breathing doesn' just solve everything) and so there is already a more natiral balance to non-verbal spells as well.


In your example, suggested rules I think there are a few issues with baance:

1) Your attempt to hide can be based on Charisma. This is a balance nightmare as some classes are charisma classes and some are not.

2) Its a skill check. Huge boost to the bard here, that is already no slouch

3) It seems to mostly be applicable for out of combat situatons, which is already an area where casters tend to perform more than OK.