D&D 5E How does the Phantasmal Force spell work correctly?

[ThePolarBear]

If I have the PF show up as a polar bear...

Do not look at me that way. I'm real, i swear!

 

[Pvt. Winslow]

Your system seems to contradict the spell description in a few places for the sake of avoiding metagaming when the spell is used against the players. I think the simpler solution is to not inform the players that they are under the effect of an illusion, as they probably won't waste their actions with "I randomly choose to push my way out of the box" if they think the box is real and sturdy. As for how to get the spell off without alerting the players (as it requires and Int save, which is kinda suspicious), it may be difficult, but there are ways. Maybe try and have your illusion mimic an effect that could reasonably requiring an Int save, or maybe the caster is using the new Lore Wizard subclass and the illusionary box on the player required a Dex save to avoid.

Well you're right in a way. I'm very transparent when I DM. I tell the player what spell is used on them, the DC of the saving throw, and exactly what the spell does. This way I avoid wasted turns, confusion, and save time. I find trying to outsmart the players with spellcasting is mental effort better spent on thinking of NPC actions and goals in the conflict.

 

[Phazonfish]

Well you're right in a way. I'm very transparent when I DM. I tell the player what spell is used on them, the DC of the saving throw, and exactly what the spell does. This way I avoid wasted turns, confusion, and save time. I find trying to outsmart the players with spellcasting is mental effort better spent on thinking of NPC actions and goals in the conflict.

Fair enough. Seems like Phantasmal Force may just be more trouble than it is worth. (Imma still probably take it next wizard I play though.)

 

[Pvt. Winslow]

Fair enough. Seems like Phantasmal Force may just be more trouble than it is worth. (Imma still probably take it next wizard I play though.)

It's definitely a spell that can open all sorts of doors to questions a DM or player has never considered before.

 

[Undrhil]

Speaking of "opening doors"... Could PF convince a guard that the KING is ordering him to unlock a door, say ... to the armory or treasury?

 

[Phazonfish]

Speaking of "opening doors"... Could PF convince a guard that the KING is ordering him to unlock a door, say ... to the armory or treasury?

I would think that would be partially about the execution and partially about the guards personality. He wouldn't naturally doubt the King in front of him is real, but he may suspect that he is being tricked if the King being there wouldn't be reasonable. He may inspect (cue investigation check) the hallucinated individual in front of him, or he may fear the consequences of not immediately heeding him and unlock the door without question. If you are the player doing the casting, make sure to engineer the illusion to keep the pressure on him.

 

[lkwpeter]

Original Post:

1.) I read a lot about "casting a black container around a creature's head" so that the creature is blinded. Or "casting some loud noises to it's ears, so it is deafend". But is that really possible?

2.) Also I would like to know, how creatures act that I cast. For example if I want to make a hostile creature beliefe that his boss is talking to him and wants it to leave his guard post. Can I interact with the illusion or change things after I cast it?

3.) What other restrictions are there? And what is the best use of it?

EDIT: The following is a personal summary of this forum thread:

Please note, that I don't claim this to be the only way of interpreting the rules. Phantasmal Force is very vague and this thread was a try to find an interpretation that is consistent with the wording of the RAW and that is consistent in analogy to other spells. These are just the main agreements of this discussion:


Effects:

• If you create a person, you do not need to know the language/appearance of the it. Like I'm a Banana said, "It's not like the illusionist is making the illusion say something, it's like the illusionist is saying, "get this concept across" and the target's mind shows the target what the concept would look like from the target's perspective. So, it relies on the target's sense of what's possible, not the illusionist's. That's part of why they're just single-target.". Furthermore this is not part of the spell's description, although some other spells explicitly say so.
• You can also create phenomena. And those can even cause status effects (e.g. blinded). (see Jeremy Crawford's Tweet here)
• Like Jeremy Crawford approved, created objects will move with the target and can also cause status effects (see his Tweet here).
• Analogous to that, if you create a hostile creature that is attacking the target, this creature would not be bound to its position. Instead, it would also follow the target, if that is trying to escape, etc. The reason is, that the creature is within the target's mind, so it won't be stuck to a position. Consider that only the "conjured" creature must be not larger than 10 foot, but not the area that it is able to move within.
• Physical interactions do NOT reveal the illusion! The reason again is that the illusion is within the target's mind. That is very different to other illusion spells.

Restrictions:

• The object must be visible for the target (spell description). So it can't be invisible.
• If the illusion is not reasonable to the target, it will probably investigate it. Consider, that illusions that look like magical spell effects are hardly "not reasonable", because the target would normally think that it's a "normal" spell effect. Contrary to this, if the target's mom that has died years ago suddenly appears in front of it, the target would probably "resist" the illusion and investigate it (as an action, after it failed the initial INT saving throw).
• After casting this spell, there is no further interaction with the illusion possible: Like Storyteller Hero said, "the phantasm can act as you "pre-program" it." The caster can neither see the illusion himself, nor can he change or interact with it after he casted the spell.

Controlling creatures (shackles, cages, etc.):

• The most important point is: This spell is a psychic force, no physic force! So, it is not possible to physically control a creature! If you create chains to bind it, these might even move a bit with the target. But the moment, the target moves away from the object, its arms/legs would simply go through the illusion. The creature would rationalize it in some way (as the spell description says), but it would be free though.
• Instead, you could try to affect the creature's motivation to do something: E.g. you could create a cage of fire. The creature might feel the heat an decide not to touch it. Or you could create something that forces the target to go prone at its own will (e.g. a poisonous fog at a specific height, so that the could duck).
• Apply the following rule of thumb to find out, whether or not a specific object would work to control a creature:
  1.) "Is the object supposed to physically affect a creature?" If yes, the effect is not possible
  2.) "Is the object supposed to only affect the creature's motivation to do something?" If yes, than it is absolutely viable and works as the spell is intended to work.

When does Phatasmal Force allow a INT (Investigation) check?

This is tough question, because the spell's description says: "The target rationalizes any illogical outcomes from interacting with the phantasm." That means two things:

1. The target rationalizes everything from interacting with the phantasm (and only with the phantasm).
2. The target rationalizes inconsistencies only from interacting.

For this reason, external influences could be one reason that raises doubts. But keep in mind that other creatures don't see the illusion!

 

[jgsugden]

[MENTION=42037]Ik[/MENTION]wpeter: Some of the conclusions you post in your summary are interpretations, but are not the only interpretation. Crawford notes in several tweets that this spell is subject to DM interpretation.

https://www.sageadvice.eu/2017/05/3...mal-force-be-restrained-by-it/comment-page-1/

For example, Crawford's advice above leads me to believe that it is up to the DM whether your chain example would effectively restrain a target.

 

[lkwpeter]

[MENTION=42037]Ikwpeter:[/MENTION] Some of the conclusions you post in your summary are interpretations, but are not the only interpretation. Crawford notes in several tweets that this spell is subject to DM interpretation.

Hey jgsugden! As I wrote this is not intended to be the only way of interpreting it. It is meant to be a summary of this thread.

https://www.sageadvice.eu/2017/05/3...mal-force-be-restrained-by-it/comment-page-1/

For example, Crawford's advice above leads me to believe that it is up to the DM whether your chain example would effectively restrain a target.

What Jeremy Crawford says is that "A DM is free to allow additional effects". Of course, this is something a DM can always do. Unfortunately, the description of Phantasmal Force is very vague. And there are only a few answers of the game designers that clearly give an insight into the RAI. Those are actually the ones I linked in my summary. But I wouldn't add the one you stated to them, because he just said that "it's okay, when you allow more than the rules say".

Most important: Phantasmal Force is an illusion and therefore cannot force a creature physically. Otherwise it would be even more powerful than spells like "Hold Person/Beast/Monster". You just need to find a way to shackle any creature with something indestructible. Binding a dragon's wings with illusionary chains? I don't think that this is intended with a 3rd level spell. And most of the replies agreed to this interpretation (not everybody though).

Treat this spell as you wish to. It's your choice. In most cases, nobody will be able to prove your interpretation wrong. But this thread was a try to find one that is consistent with the wording of the RAW and what is consistent in analogy to other spells.

 

[Rhenny]

Here's my question for DMs...

If a player does use Phantasmal Force to create a ring of burning flames around the target, how does the DM decide what action the target takes based on the perceived situation?

Is it just a judgment call or do the DMs out there make some kind of check?

Scenario 1: Flames all over the target and surrounding it.

Scenario 2: Just a wall of flame around it so that the target is cut off and has to decide whether or not he/she should try to jump through the flames.

If the flames obscure vision, can the creature attack targets? Do they attack at disadvantage?