D&D 5E Invisibility, non-instantaneous spells, and spell effects

[Irlo]

100% agreed. Honestly, the system is incredibly open and flexible about what you can combine, interrupt, run in parallel or sequentially, etc.. The limits are few and far between,

Yes! I'm not seeing any gain in trying to define, limit, and analyze everything as if the rules are logical rigorous and internally consistent (except maybe as an intellectual exercise, which IMO is futile), since there are so many discrepanices and edge-cases and oversights and flexibility in the system. We can mess around with how the narrative interacts with mechanics and with how sequential and simultaneous resolutions combine in the narrative, and we can do it on a case by case basis, and have good, interesting, creative, fun games.

(Others who don't agree also have good, interesting, creative, fun games.)

 

[Maxperson]

The spell invisibility is not instantaneous in duration, nor are the spell effects specified to be instant. Can I cast a readied magic missile to use when the target begins to turn invisible? Why or why not?

YES. It takes only a fraction of a second to use a spell as a reaction. The invisibility spell does not specifically state that the invisible condition is applied instantly, so there is some small but perceptible duration of time after completion of spell that the target is visible and fading away. Plus, I like the idea of a quick but gradual fade-away as the magic kicks in.

NO. The magic missile spell is only valid on a target that the caster can see. Spell effects occur instantly upon competion of the spell unless stated otherwise, and don't require an instantaneous label or descriptor to be instantaneous. [Is there a rule to that effect, or is it just a reasonable ruling on the part of the DM?]

Coming into this late. No. You don't "begin" to turn invisible. You turn invisible. Alternatively, even if you do rule that you "begin" to turn invisible, the trigger must finish before the readied action goes off and the target is invisible by then.

 

[Irlo]

Coming into this late. No. You don't "begin" to turn invisible. You turn invisible. Alternatively, even if you do rule that you "begin" to turn invisible, the trigger must finish before the readied action goes off and the target is invisible by then.

Perfectly reasonable. That is, then, an exception to the idea that anything instantaneous is labelled as such. I agree.

 

[Maxperson]

Perfectly reasonable. That is, then, an exception to the idea that anything instantaneous is labelled as such. I agree.

When I said that, though, I was talking specifically in the context of "effects." Invisibility is not an instantaneous effect, and turning invisible is not an effect at all. The moment you turn invisible is potentially perceivable and most likely is over very, very quickly(instantly), but even if you can perceive it for a readied action, the trigger has to complete first and the readied Magic Missile won't work.

 

[Irlo]

When I said that, though, I was talking specifically in the context of "effects." Invisibility is not an instantaneous effect, and turning invisible is not an effect at all. The moment you turn invisible is potentially perceivable and most likely is over very, very quickly(instantly), but even if you can perceive it for a readied action, the trigger has to complete first and the readied Magic Missile won't work.

i have to admit that I have no idea what you mean by effect, but that’s all right. I’d rather leave it be. Thanks for your replies.

 

[Lyxen]

i have to admit that I have no idea what you mean by effect, but that’s all right. I’d rather leave it be. Thanks for your replies.

There is one proper definition of the effect of a spell, and it's the entire textual description: "Each spell description in Chapter 11 begins with a block of information, including the spell’s name, level, school of magic, casting time, range, components, and duration. The rest of a spell entry describes the spell’s effect."

In the DMG, there is a section about effects, and it's also pretty much straightforward: There is an exhaustive list of what the game considers features ("Game features include spells, class features, feats, racial traits, monster abilities, and magic items."), and these feature have effects.

And that's all there is to it in terms of RAW, in general. Now, some spells have more than one effect, but these are rare and mentioned specifically in the spell description, for example Guards and Wards: "When you cast this spell, you can specify individuals that are unaffected by any or all of the effects that you choose. You can also specify a password that, when spoken aloud, makes the speaker immune to these effects.
Guards and wards creates the following effects within the warded area."

All of this to say that "effects" is, as usual in 5e, not a well defined term, except for spells.