What level should a spell that lets a character briefly attune to an extra item be?

I am considering adding a homebrew spell to a game I DM. Here is the exact wording I intend to use:

Superior Attunement

8th level transmutation

Casting Time: 1 action

Range: Touch

Components: V, S, M*

Duration: 8 hours

You touch one creature and one magical item which requires attunement, but to which no creature is currently attuned. At any time within the next eight hours, the affected creature may, as a bonus action, touch the affected item and instantly attune to it without requiring an attunement slot. The creature remains attuned to the item for one minute. After one minute, the spell and the attunement end.

The spell ends early if the creature falls unconscious or if any creature attunes to the magical item. No creature can use this spell to attune to any more than one item at a time.

The creature must still meet any specific requirements this item has for attunement (class, alignment, etc.). If a creature attempts to use this spell to attune to an item whose requirements it does not meet, it suffers the same consequences as it would in the normal attunement process.

* (Any magical item that requires attunement, but to which no creature is currently attuned)

I have tentatively decided this spell should be an 8th-level spell. I feel this strikes a good balance. This spell is a utility spell, and who wants a 9th-level utility spell? But it has the potential to make a character quite powerful for a short period of time, so I don’t want a character to be able to cast it more than once a day.

Does this seem like a reasonable spell level? If not, what level should this spell be

Is this Portent-like spell balanced?

As a divinitation wizard, I love the portent mechanic. There is little better than pointing at an ally about to unleash their biggest attack on the BBEG and telling them, ‘you just rolled a 20’ (or whatever number I have that’s high enough for them to hit). It makes me feel like a proper diviniation wizard.

Unfortunately, I have found there are few combat spells that have the same feel of being able to directly influence others’ fortune available. That is why I have tried to capture the feeling of portent in spell form.

Alter Fate

2nd level divination

Casting time: 1 action

Range: sight

Components: V, S, M (a glass bead)

Duration: Concentration, up to 1 minute

By focusing your inner eye on the near future you are able to influence the weave of fate. When you cast this spell you roll 1d20 and record the number. As a reaction, you can replace any attack roll, saving throw, or ability check made by you or a creature that you can see with this foretelling roll. You must choose to do so before the roll. This foretelling roll can only be used once.

At higher levels: When you cast this spell using a spell slot of 3rd level or higher, you may add or subtract 1 for each spell level above 2nd to the die roll, with a minimum result of 1 and a maximum result of 20.

I am having trouble finding a proper way to estimate this spell’s power level. I realize that there is a reason divination wizards only receive their third portent die at lvl 14. That is why I have tried to limit the spell by requiring concentration and an action to cast.

The part I am most worried about being unbalanced is the ‘at higher levels’ part. Does the this make it too easy to get critical hits or misses?

Why can’t the “Variant: Imp Familiar” be found with the Find Familiar spell?


The Find Familiar spell describes a familiar

The Find Familiar spell description explains what a “familiar” is. It describes its properties — acts independently, can’t attack, can deliver spells, can be dismissed into a pocket dimension, etc.

The PHB uses “familiar” as a term, expanding its properties in some cases, e.g. Pact of the Chain:

Pact of the Chain
You learn the Find Familiar spell and can cast it as a ritual. The spell doesn’t count against your number of spells known. When you cast the spell, you can choose one of the normal forms for your familiar or one of the following special forms: imp, pseudodragon, quasit, or sprite.
Additionally, when you take the Attack action, you can forgo one of your own attacks to allow your familiar to make one attack of its own with its reaction.

So the Warlock’s familiar can be an imp, pseudodragon, quasit, or sprite, and it can attack.

“Variant: Familiar” describes additional familiar properties

Notice that imp, pseudodragon and quasit all have the “Variant: Familiar” block and there are no other creatures in the MM with the “Variant: Familiar” block. That block describes additional familiar features: first one is the 1-mile telepathic link, and second one depends on the creature type (for instance, Imp gives its master the Magic Resistance trait). That block does not describe any other familiar’s properties. It doesn’t explain anything that is already described in the Find Familiar spell, and it still uses the “familiar” term. It is logical to assume that it is the same “familiar” as the PHB describes.

From my understanding, “Variant: Familiar” expands base familiar description, like the Pact of the Chain does:

  1. General familiar properties are given in the Find Familiar spell description.

  2. If the spellcaster is a Warlock and they chooses the Pact of Chain feature, the familiar properties are expanded, giving more potent familiar as a result.

  3. The familiar properties might be expanded even more, if the familiar is Imp/Quasit/Pseudodragon and the DM uses the “Variant: Familiar” optional rule.

It goes well with the “specific beats generic” rule:

  • Familiar can’t attack (generic) but it can with the Pact of Chain (specific).

  • The spellcaster can share familiar’s senses within 100 feet (generic), or 1 mile with several kinds (specific), providing the DM uses the variant rule.

So why in fact does it not?

Several answers (like this one) assume that in fact “Variant: Familiar” rule describes a sort of “another” familiar with completely different properties. It can attack, but can NOT deliver spells, and if it dies — it’s gone forever. How to obtain this familiar remains a mystery. It is still called a “familiar” though.

That seems purely homebrew for me, but is treated as official rulings. It is also being said these creatures cannot be found with the Find Familiar spell. What is the source of this assumption? What are the properties of this “another familiar”, and where they are described?

@SevenSidedDie mentioned that all “Variant: X” in the MM mean a somewhat special creature:

… a variant is just an alternative stat block for a given creature, so that it works slightly differently from the common variety of that creature.

The idea of “variants” is that, just like not every human is identical

A familiar variant of a creature is just the stat block to use for a creature that has somehow agreed to serve as a familiar for a spellcaster.

That actually supports the idea that Warlock should have the magic resistance trait from the imp, not contradicts it.

The Warlock summoned an imp as a familiar — therefore, that particular imp agreed to serve as a familiar. The DM uses the variant rule. Why shouldn’t the imp give the magic resistance trait, as the “Variant: Imp Familiar” describes?

It is just a spirit that takes a particular form

That answer explains it that way:

the Warlock’s familiar isn’t any sort of pseudodragon, let alone one with the variant. It’s a spirit that takes the form of a pseudodragon

But that reasoning does not work with the imp. Find Familiar implies that the imp familiar is an imp:

the familiar has the Statistics of the chosen form, though it is a celestial, fey, or fiend

So a fiend can be a familiar, and Imp is a fiend.

Can a Spell cast through a War Caster Reaction be Twinned?

I’m not sure if this interpretation of RAW is correct or if there is any RAI that would decide if twinning a warcast spell is valid. Is there anything that makes it explicit that a single target spell cast through the War Caster feat can or cannot be twinned?

War Caster

When a hostile creature’s movement provokes an opportunity attack from you, you can use your reaction to cast a spell at the creature, instead of making an opportunity attack. The spell must have a casting time of only 1 action and must target only that creature.

From what I can tell, War Caster takes place during the triggering of the reaction. You replace a opportunity attack with the casting of a spell, or essentially the Cast Spell action. Once you select a spell that takes 1 action and is targeting only the creature that has provoked the Reaction, the requirements of War Caster are satisfied.

Metamagic: Twinned Spell

When you cast a spell that targets only one creature and doesn’t have a range of self, you can spend a number of sorcery points equal to the spell’s level to target a second creature in range with the same spell (1 sorcery point if the spell is a cantrip).

Based on the phrasing of this metamagic feature, you select to twin a spell after you have selected targets. That would be after War Caster’s conditions have already been met.

Now, Twinned Spell does not work on things like Fire Ball, because it can target more than one creature, even if it currently doesn’t. I’m not sure if this can be applied to War Caster in the same way though, because what is causing that to be the case is Twinned Spell. And if you can’t use something like Fire Bolt because it could be twinned and that makes it violate the condition “must target only that creature” that would imply that you can’t twin Fire Bolt ever because “that targets only one creature” would also apply. So if you can’t twin a warcast spell, you shouldn’t be able to twin any spells, from what I can tell. That leads me to conclude that you must be able to twin a warcast spell. Twinned Spell does not apply retroactively to itself, so it would make sense it doesn’t apply retroactively to War Caster.

What information exists that makes this clear and less reliant on just trying to guess the order of operations for when War Caster’s condition stops applying?

Do you need to hold concentration on a spell when you casted it with a spell scroll?

I’m currently running Out of the Abyss, and my group is about to encounter a mage with a description that says

If the characters become hostile, [the mage] orders them to depart, lest they provoke the wrath of his all-powerful master. If attacked, he uses his globe of invulnerability scroll, casts fly on himself, and flies into the chasm.

Both spells are concentration spells so I’m not sure if this is an error in the module, if you don’t need concentration for scrolls, or if I read the paragraph wrong and he just uses the scroll first, runs away, and then proceeds to cast fly and fly away.

So my question is: Do I need to hold concentration for concentration spells cast with a spell scroll?

How unbalanced would a feat that allowed access to other spell lists be?


Background

There are times where I feel like a certain spell would very much suit a certain character or concept, but because it’s not on that classes’ spell list, they can’t have it.

The classic example in my mind is that Tempest Domain Clerics can’t have Storm of Vengeance (even though it used to be on the Cleric spell list in previous editions) or Whirlwind or other spells that suit their theme. As it stands, you’d need to take 17 levels in Druid (or 18 levels in Bard for their last use of Magical Secrets) to get those spells, at which point you’re not really a Tempest Cleric anymore, you’re a Druid or Bard with a dip in Cleric.

I wanted to come up with a way to allow certain classes access to certain spells that they otherwise can’t get. I thought a feat might be an acceptable cost for this benefit (aside from a DM just saying “just have the spell anyway” or “I say that this spell is on the Cleric spell list for my games”, etc).

Proposal

My proposed feat would be that, if you have the Spellcasting class feature (i.e. you are of a class that can already cast spells) or Pact Magic (because Warlocks spellcasting class feature isn’t called Spellcasting), then you can gain access to one other classes’ spell list and “they are X spells for you” where X is your spellcasting class (if you’re a multiclassed spellcaster like a Bard/Sorcerer, then pick one of your spellcasting classes).

So for a Cleric gaining access to, say, Bard spells, the Cleric would use Wisdom rather than Charisma; this idea is based somewhat on the Divine Soul sorcerer, who has access to all Cleric spells but uses Charisma to cast them.

Question

My question is: Is this balanced? If this is overpowered, would restricting it to only a school or two from the other spell list help to balance it? If this is underpowered, I’d probably throw in a +1 to your spellcasting ability to help balance it. Or is this so broken in a way that I haven’t anticipated that I just shouldn’t do this at all? Perhaps this is something that is only unbalanced if Warlocks are included (so simply excluding them from this removes a bunch of balance concerns)?

Also note that, although I’ve recently asked questions about Rangers using the Wizard’s spell list, this is actually nothing to do with that. However, I am currently assuming that Paladins, Rangers, Eldritch Knights and Arcane Tricksters are to be included in my proposed feat. Any or all of these can be excluded as I suggested for the Warlock above if this is unbalanced.

What would the balance implications be of removing the spell school restriction of learning spells for Eldritch Knights and Arcane Tricksters?

Both Eldritch Knights (a subclass of fighters) and Arcane Tricksters (a subclass of rogues) pull their spells from the wizard spell list, albeit in a limited way. The way in which they do this is by only being allowed to choose spells from the evocation and abjuration schools, in the case of eldritch knights, or from only choosing from illusion and enchantment, in the case of arcane tricksters. Both classes also get very small amounts of any spell they want from the wizard spell list.

How unbalanced would it be to allow both these subclasses to choose spells regardless of school from the wizard spell list? Good comparisons may include comparisons to half casters, and of course to changes in how these classes could play.