What happens when you banish an elemental creature that was formed/born on the Material Plane?

Background: In one of our campaigns we have quite a few Elementals that are forming in the material plane, as opposed to forming on an elemental plane. The elementals are otherwise identical to the ones appearing in the Monster Manual.

We are coming up to the levels where some of us can choose the 4th-level spell Banishment as a spell. I was wondering if casting Banishment on an elemental formed on the material plane would a) banish it to an elemental plane and not return or b) be only temporarily banished to a demiplane and appear back onto the material plane when the spell ends.

The way I see it is that it would have to do with the interpretation of what is “native to the plane” and “home plane” in this case.

The description of the Banishment spell (PHB, p. 217) says:

You attempt to send one creature that you can see within range to another plane of existence. The target must succeed on a Charisma saving throw or be banished.

If the target is native to the plane of existence you’re on, you banish the target to a harmless demiplane. While there, the target is incapacitated. The target remains there until the spell ends, at which point the target reappears in the space it left or in the nearest unoccupied space if that space is occupied.

If the target is native to a different plane of existence than the one you’re on, the target is banished with a faint popping noise, returning to its home plane. […]

I suspect it would banish these home-grown elemental creatures to a demiplane in the case of our campaign; unless we were on another plane, in which case it would be banished to the material plane as this is its “home plane”.

There is this question which gives an answer of sorts: What determines a creature's native plane for the Banishment spell?, but I would like a more concrete answer if possible to the scenario I present above.

Does using material components in spells make D&D 5e more challenging?

In my campaigns we typically don’t rely on material components, allowing casters to use any spells as long as they have the right spell slots available. My impression is that using components would be more challenging, since players’ spells would be limited by gold, component availability, and carry weight. Is it significantly more challenging or cumbersome to include this feature? How do others incorporate components?

Is material from Adventures of Middle-Earth adaptable for Rolemaster?

I am currently running a Rolemaster campaign set in Middle Earth, TA 1640. I have source material for Rhudaur (where the group is right now), Rivendell, and Angmar.

I have come across this book bundle which features a lot of interesting regions, but the system is not Rolemaster or MERP; it is “Adventures in Middle-Earth”.

Is it going to be easy to use this material for Rolemaster, or are they very different systems? What age is it set in?

Are there any examples in published D&D material of how to destroy a lich’s phylactery?

According to the D&D 5e Monster Manual, regarding destroying a phylactery, it says:

Destroying a lich’s phylactery is no easy task and often requires a special ritual, item, or weapon. Every phylactery is unique, and discovering the key to its destruction is a quest in and of itself.

— p. 203, Death and Restoration

However, no further information is given on how this is typically done, or what is involved specifically.

I get that this is meant as a plot hook for the DM, and that the DM is meant to fill in the blanks as befits their story/campaign, and that the intention here is that different lich’s phylacteries must be destroyed in different ways, rather than a one-size-fits-all method for destroying any phylactery.

However, it would be easier for me to come up with something if I had some examples to work with from existing adventures or additional lore on liches not included in the D&D 5e Monster Manual. Is there anything published in any edition of D&D that describes how to destroy a (specific) lich’s phylactery?

Does a dragon need material components, specifically body bits, for a Simulacrum spell?

Please consider an ancient Green dragon with the variant ability to cast spells. She would like to cast Simulacrum.

Monster Manual Page 86 / Variant:

VARIANT: DRAGONS AS INNATE SPELLCASTERS: Dragons are innately magical creatures that can master a few spells as they age, using this variant.

A young or older dragon can innately cast a number of spells equal to its Charisma modifier. Each spell can be cast once per day, requiring no material components, and the spell’s level can be no higher than one-third the dragon’s challenge rating (rounded down) . The dragon’s bonus to hit with spell attacks is equal to its proficiency bonus+ its Charisma bonus. The dragon’s spell save DC equals 8 +its proficiency bonus + its Charisma modifier.

As noted she is CR: 22 with 19 charisma – giving her four spells to cast once per day / 7th level spell maximum. No problems thus far. She is concerned about the material components for this Simulacrum spell…

Components: V, S, M – Snow or ice in quantities sufficient to made a life-size copy of the duplicated creature; some hair, fingernail clippings, or other piece of that creature’s body placed inside the snow or ice; and powdered ruby worth 1,500 gp, sprinkled over the duplicate and consumed by the spell.

… but she realizes (thanks to ‘variant’, above) that she casts all her spells ‘requiring no material components’. This is her lucky eon! She will have to choose fun spells like Awaken and Reincarnate so as to build up an immortal army of her favourite treasure-people-beasts! But she digresses.

This zero materials required means she need not worry over the expensive powdered ruby – nor even the snow for that matter. But what of the hair, clippings (or ‘other body parts’)? If ANY components are allowed, can she cast any humanoid or beast that has ever lived in history? She could theoretically magic-pretend that she procured these left over parts before that person or beast died. Can she even create duplicates of imaginary people with this casting? Is there a way that anyone could defend themselves from being copied? Some may have Mind Blank or Protection vs. Nasty &/or Goodness or reside on another plane of existence. How does one defend themselves from this 3D printer of doppelgängers?

The reason this is relevant: If she has access to any body parts without impunity, she could conjure up any high cleric or archmage in existence at no cost. The next day she could conjure up another, for free. This is bizarrely powerful. To be honest, even the ability to conjure up the same archmage from a specific ball of hair, gaining Wish on a daily basis (without limits) is a bit extreme.

Long story short: A dragon casts spells without need of ANY components. What kinds of Simulacrum persons &/or creatures can they make?

Does UA Psionic Wizard’s Though Form let you ignore non-consumed material components with a cost?

UA Psionic Wizards get a special ability called Thought Form where they become beings of pure energy. Part of that ability is Psionic Spellcasting.

Thought Form

Psionic Spellcasting.

When you cast a spell while in thought form, you can cast the spell psionically. If you do so, the spell doesn’t require verbal, somatic, or material components that lack a gold cost.

What does this mean? Functionally, you have an arcane focus as a class feature so material component usually doesn’t matter.

This means you can’t cast spells like Glyph of Warding (200gp dust, consumed) for free. However, can you cast spells that don’t consume the materials like Chromatic Orb (50gp, diamond)?

Otherwise, the “no material component” seems irrelevant as you have your psionic focus already to activate the ability.

Do the Warlock’s Pact of the Tome cantrips need their material components?

I want to create a celestial warlock and I want to have Shillelagh as one of my Pact of the Tome cantrips.

I also wanted wooden staff as an arcane focus so I can use melee and free up my other hand.

Are the Pact of the Tome cantrips treated as warlock cantrips, which would let me use my arcane focus, or would I need a separate Druidic focus?

For example, to cast Shillelagh you normally need to have mistletoe and a shamrock leaf. Would my warlock focus let me forego the need for the material components, or would I need a druidic focus too?

Does the Githyanki Racial Spellcasting ignore all Spellcasting Components, or only the Material Components?

The Githyanki Player Character Racial Option permits limited casting of a few spells, which is similar to the spellcasting granted to several other Racial Options; but unlike most other options, this feature also specifies that the spellcasting components are not required:

Githyanki Psionics. You know the mage hand cantrip, and the hand is invisible when you cast the cantrip with this trait.
    When you reach 3rd level, you can cast jump once with this trait, and you regain the ability to do so when you finish a long rest. When you reach 5th level, you can cast the misty step spell once with this trait, and you regain the ability to do so when you finish a long rest.
    Intelligence is your spellcasting ability for these spells. When you cast them with this trait, they don’t require components.

Githyanki, Mordenkainen’s Tome of Foes, pg. 96

Does this mean that the verbal and somatic components for these spells are ignored, or just the material components, like required for the jump spell?

Why can astral projection only be used on the material plane

So I was reading up on astral projection, and it said that you have to be on the material plane to use it. So that made me wonder if you have to be on the material plane does that imply that there’s something special about it that all other planes lack or does the astral plane just happen to be connected in a certain way to the material plane that allows this and all other planes don’t.

Would it be game-breaking to allow a Warcaster to cast spells with material components while wielding a shield and spear?

The general consensus on this site is that the Warcaster feat does not grant the ability to cast spells with material components when wielding two pieces of equipment because the caster needs a free hand to interact with their arcane focus or pouch.

Assuming the spellcaster is using an arcane focus, would there be significant balance ramifications to lifting this limitation?

This would essentially amount to saying that the Warcaster feat grants the spellcaster the dexterity to interact with their arcane focus when wielding two pieces of equipment.

In my experience, I’ve found that material components are functionally equivalent to somatic components in every case except those where GP-equivalent components are consumed. So right now I can’t see any immediate negative effects of lifting this limitation. Am I missing anything?

For additional context, the spellcaster in question is a Warlock in my campaign that’s using a combination of the Warcaster and Polearm Master feats while wielding a shield and spear.

Additionally, my group tends to be very flexible and lax with components, typically treating them as little more than “flavored” somatic components, except in the case where the components are consumed.