Wish and the Ring of Spell Storing

Why mention spells of "level 8 or lower" if everyone is going to be casting every spell at level 8, because thats what will happen if your interpretation is how it works?  

Because not necessarily you might want to upcast a spell. You can if you want, you probably should if yoou are in battle, but you don't have to. It's your wish. 

Quote from Jayce_Danathar >>

Why mention spells of "level 8 or lower" if everyone is going to be casting every spell at level 8, because thats what will happen if your interpretation is how it works?

Because not necessarily you might want to upcast a spell. You can if you want, you probably should if yoou are in battle, but you don't have to. It's your wish.

Also, Simulacrum can't be upcast :)

Quote from kenclary >>

Also, Simulacrum can't be upcast :)

Any spell can be upcast. It's just that some don't derive any benefits from doing so. 

Quote from Pantagruel666 >>

I would note that there is a problem with how upcasting is written in the rules, in that the text for upcasting typically only applies when cast with a spell slot. Thus, RAW, when you use 3 charges from a wand of magic missiles to cast magic missile as a 3rd level spell, you only get 3 missiles. This is pretty obviously not intended, however (also, it doesn't apply to the various summon spells, as they explicitly use the spell's level in the stat block whether or not you use a spell slot).

Fortunately, the rules have a "specific beats general" principle 🙂

Quote from Natrel >>

Fortunately, the rules have a "specific beats general" principle 🙂

Which would be relevant if the rules said anything specific.

1. The rules tell you what happens when you cast magic missile as a first level spell.
2. The rules tell you what happens when you cast magic missile as a third level spell with a third level spell slot.
3. The rules do not tell you what happens when you cast magic missile as a third level spell without using a spell slot.
4. The wand of magic missiles says the spell is cast as a third level spell, but does not say it should be treated as having been cast with a third level spell slot.

It's pretty clear that RAI is that (2) and (3) have the same result, but RAW doesn't actually say that.

Quote from SunIsGettingRealLow96589 >>

What Wish actually says: "The basic use of this spell is to duplicate any other spell of level 8 or lower."

Why mention spells of "level 8 or lower" if everyone is going to be casting every spell at level 8, because thats what will happen if your interpretation is how it works?  

Magic missile? Cast at level 8. Fireball? Cast at level 8.

Because every rule that mentions upcasting says you need to use a higher level slot. And theres no slot being used here. In twinned metamagic, it explicitly says how the spell is effectively upcast by one level. But there is no mention of upcasting, no mention of slots, no mention of anything about changing  "effective" levels in Wish.

So you use base level spell.

 
What part of "Wish doesn't actually cast or upcast the spell whose effect you're duplicating" do you not understand?
Wish says it itself: "If you use it this way, you don’t need to meet any requirements to cast that spell, including costly components. The spell simply takes effect."

That's also the reason why you don't have to worry about the duplicated spell's casting time, or even whether it's in your spell list: you're not actually casting it, so you don't even need to know how to.
Normally, to cast a spell with your spellcasting feature, you need to have it in your spell list and have it prepare, and you have to provide the components, respect the casting time, and consume a resource (charge, daily use, spell slot, special action).
It's during that phase that the rules of upcasting apply. You can't upcast a spell by consuming a charge (unless the item specifically casts at a specific level, in the case of Magic Missile, which doesn't constitute "upcasting" as Pantagruel mentioned) or a special action (although some actions mention a specific level, like the Pit Fiend's Fireballs). And THEN, after the casting phase is over, you get to read the description of the spell as it takes effect.

Wish by-passes all that and skips straight to the "takes effect" phase.
That's why any rule related to casting does not apply to Wish's basic use: you never get the point where you need to consider them.