There is a reason no one uses illusion spells.
Too many ogres instantly realizing that the shadows aren't just right, or city guards that literally know every single street in a massive city and KNOW there isn't supposed to be a wall there.
I've seen plenty of illusion and enchantment spells that are effective in play. It all depends on the DM and the Players and the communication/trust between those parties. The same is true for something like a persuasion roll, where the effects of a success are fuzzy but still possible to be adjudicated.
The reason why I'm sympathetic to Vaalingrade here (and that general position in this thread) is that without robust, table-facing archetecture to resolve the following question:
* Does this particular guard know every single street in this massive city so well?
* Were they out on a bender last night with their mates?
* Did they have a terrible night of sleep due to fallout with a friend/loved one do they have an affliction like insomnia or just general anxiety about a tough day on the job tomorrow?
* Are they contemptuous of their boss or hierarchical corruption within their ranks and...maybe they pierce the illusion but they're quite happy to see things go wrong for their ranking officer?
...how do we know the GM is performing a legitimate (in all ways that a thing can be legitimate and illegitimate, including fairness and competency) conception and extrapolation of a complex imagined space? There are so many variables that could possibly impact "whether this particular guard sees through the illusion" or "is there even a guard there to see through the illusion in the first place?"
When one of the primary priorities of play is for the GM to somehow conceive of an enormously complex system (a single person is complex system enough!) >
* run a mental model of all the varying parameters of this system >
* pick the results of
this instantiation of that model over
that one (and any complex, legitimate model should have profoundly differently results with respect to "guard on duty piercing illusion" if run 1000 times) and do so fairly as a neutral referee without softballing or being intentionally adversarial >
* successfully convey the outputs of their complex mental model in a way that is comprehensible to the players (foregrounds the stakes/conflict and telegraphs potential consequences of subsequent interaction with the imagined space so the player can infer/build out the risk profile and opportunity cost of
this move made vs
that move made) >
* all
without the aid of a UI that converts imagined space dynamics to player in meat space
...well, that is just a hell of an ask for both the GM and the players and stresses human competency (breadth and apex) and communication and comprehension and patience and trust to its limits. If I'm a player, I have to (a) believe you can model all of this stuff, (b) believe in your methodology of parameterizing a complex model (like above) and legitimately run it in your head in-situ, (c) believe that you're making the correct (meaning neutral, fair, sensible) decision in picking this instantiation of your model vs one of the hundreds of other ones (where the state of the guard is different), (d) believe in your capacity to convey all the relevant information so I can upload it and build out my decision-space, and (e) believe in myself to comprehend all of this stuff without the aid of a UI (particularly when the stakes are high and consequential).
Its a hell of a lot to believe and a hell of a lot to ask.
I was discussing a Blades in the Dark combat scene that we had to cliffhanger for this Sunday. Its been built out in the following way mechanically:
1) Grinders mutant barring the way in the tight quarters of Sausage Alley to the junkyard that houses their "Allamo" (a bunker under a scrap pile). A 3rd party gang (the brutal Billihooks) has their slaughterhouse as the northern building of this alley (with an alley-facing entrance/exit). These things will inform the Position and Effect and Consequence-space for various Action Rolls (as well as potential Devil's Bargains).
2) Mutant is Quality 2, Master Threat, Large Thug
3) 2 x defenses (these are discrete so you can attack them separately):
* Armor that you have to destroy to kill him. You need Great Effect to destroy his armor.
* Bracer on Massive Wrists/Arms (he has huge ape index) - "Break Guard": This is a 6 Tick Tug-of-War Clock, starting at 2 for his guard. You have to get to 6 to Break his Guard to kill him. I'm going to use Complications to tick it back down.
Now there are a host of several other intersecting components in this Assault Score (after a massive Score last session put the Crew to At War status with The Grinders, the Crew has decided that 3 of them are going to take the fight to the Grinders and try to wipe them out while the other two fulfill an obligation to The Red Sashes by breaking into the Spirit Warden's Bellweather Crematorium and "break out" with a Red Sash ghost that is about to be creamated in the electroplasmic spirit removal plant!) that will inform Position, Effect, player move-space, Consequence-space, etc. But let us just focus on 1-3 above.
There is no one on this board...not a single soul...who is more confident in their ability to build out and articulate a fight scene in a TTRPG (due to the varying intersections of my background/experience/expertise). But if you ask me to go with my own mental modeling of the above + fair and objective model run selection + executing the difficulty of articulating complex concepts in a table-time and pacing-friendly way to players such that they can confidently build-out the risk profile and opportunity cost of their deicison-space and confidently execute a move (like a highly capable Scoundrel would in the world of Duskvol)...without the aid of all of the individual and integrated aspects of Position, Effect, Threat Level, Resistance Rolls, Stress, Clocks/Ticks, Harm, Armor, Special Armor, etc etc etc to serve as a User Interface?
I'm going to kindly say "no thank you." When I say "no thank you" I'm coming from a place of simultaneous extreme confidence yet extreme humility (at my limitations and the limitations of human conversation and the limitations of players).
So again...in my assessment, its just a massive ask (of a GM of the limits of human conversation of the limits of players).
Or, in other words, this post from
@hawkeyefan
I think the issue is that there is no way for a GM to actually convey the amount of information or level of detail to the players that would equal the info available yo the characters simply by being in their environment. It simply cannot happen.
So if we accept that, then it’s less about precise correlation than it is about informing the players sufficiently enough that they can make decisions for their characters.
That some of this information may be beyond what the character knows isn’t really all that relevant, it’s more that the information provided to the player informs their decision making just as in-world information would inform the character.
This is the reason for rules. They’re the translation from fiction to non-fiction, character to player. The less these are known to the player, the more we move into a Mother May I kind of situation. The reason many view that as problematic is that without the rules, we’re putting the GM in a position to achieve the impossible: to create a situation that’s as vivid and clear to the players as it would be for people experiencing things firsthand.
Simply put; informed player ——> informed character.
That the GM is also then responsible for determining the results of choices made by players, consequences for the characters’ actions, just compounds the concern. I’m not averse to GM judgment, I just prefer when that judgment is more related to the process than to the outcome.