What are the rules for upgrading existing magic item?

This question comes from the comments on my previous question.

In short, if I have for example a Belt of Incredible Dexterity +2 (4,000 gp), and I want a Belt of Incredible Dexterity +4 (16,000 gp), can I simply go to a wizard and pay the difference and wait for the necessary days to have the item upgraded?

In this case, since the cost goes from 4k gp to 16k gp, I’d have to pay the wizard 12k gp and wait 12 days, while s/he would have to spend 6k gp to perform the task and keep the other 6k gp as profit.

However, the only example I found in the rules, is of a wizard upgrading his/her own item:

Example: Patrick’s wizard decides to use his downtime to increase the armor bonus on his bracers of armor +1 to +3. The price difference between the two types of bracers is 8,000 gp, so Patrick’s wizard must spend 8 days and 4,000 gp (half the 8,000 gp price difference) upgrading his bracers’ magic. If he has fewer than 8 days before the next adventure, he’ll need to finish his crafting while traveling or use accelerated crafting in town to speed up the process.

Change Shape: what happens if you try to meld an item containing a creature?

So fun question that came up in another one of my games.

A player (me) is currently an adult gold dragon via True Polymorph; duration is currently "until dispelled".

The Change Shape ability says that items being worn/carried can be chosen to meld into the new form. Now if I am carrying a coffin with a living creature in it, what happens to the creature if I try and meld the coffin into me?

The creature in question is alive but is in no way concious or able to object in anyway.

A ruling in the case of a normal coffin and another with a magically closed coffin would be greatly appreciated.

Can the artificer’s spell-storing item affect a Rakshasa?

My character is being hunted down by 3 Rakshasa. The character is aware they possess limited magic immunity which reads as follows:

Limited Magic Immunity. The rakshasa can’t be affected or detected by spells of 6th level or lower unless it wishes to be. It has advantage on saving throws against all other spells and magical effects. [Basic Rules, p. 341]

As a level 11 Artificer, I can store spells into a Spell-Storing Item.

Spell-Storing Item

At 11th level, you learn how to store a spell in an object. Whenever you finish a long rest, you can touch one simple or martial weapon or one item that you can use as a spellcasting focus, and you store a spell in it, choosing a 1st- or 2nd-level spell from the artificer spell list that requires 1 action to cast […].

While holding the object, a creature can take an action to produce the spell’s effect from it, using your spellcasting ability modifier. […] [ERLW p. 58]

Since the item is just "producing the spell’s effect" should it be treated as a magical effect instead of a 1st or 2nd level spell?

Is the Rakshasa immune to the spells produced by the item? Or would they just have advantage against saving throws?

How to Initially Ward Player Away from Key, Story-Driving Item?

I have an item in my DnD-5e story that is intended to have a warding effect, in that the story requires that it have a "magical ability" with the intention of warding or repelling people away from that location. However, this is an item the players must eventually obtain as it is crucial for the story.

My initial thought was to allow this item to use a spell like this Repel spell, if the players attempt to interact with it, but they need some way to overcome this spell and actually obtain this item.

How can I allow this item to ward players players away, while still having a way for the players to circumvent the warding effect and obtain said item?

How can a druid keep ahold of an item while using wild shape?

In the interest of making a bouncing ooze (via Cave Druid) that utilizes Leaper’s Libation and a level of Black Powder Vaulter to jump around everywhere, I wanted to use an Akitonian Blade (tiny-sized) in order to boost my acrobatics checks for obvious reasons.

However, I have a set of problems that come with it:

  1. Oozes have no hands. (Solved via Arms of the Marilith)
  2. When I wild shape into an ooze, the blade merges into me, preventing me from obtaining it’s bonuss since I’m not wielding it anymore.

Given that I don’t want to waste actions dropping the Arms of the Marilith, picking them up, and re-equipping them every combat, how can I keep ahold of them while wild shaping?

I gave a too powerful magic item at too low level for a bad reason, what to do?

When a paladin in the game I run went into the local store ran by an ex adventurer, he went to the back to see the fancy swords, and asked if any looked like his holy symbol. The god he follows is illegal in that world, so I thought it would be cool if the shopkeep had one, so I narrated an old padded box that she takes out with a sword that exactly matched his holy symbol (which is a sword in a cicle). I narrated a tingling feeling when he touched it. But then I realized; he’s level two, the game has barely started, and I had him buy what seems to be a potentially extremely powerful magic item for 60 gp. I don’t want to backpedal lamely and make it weak, but it seems like a sorta dumb way to get a great item. What should I do?

To clarify, neither I nor the player know what item he has. I don’t want to make it a lame +1 sword or something, when I narraed it as something powerful. I was thinking of teiring it, at 1st teir it does nohing, second teir 1d6 extra radiant damage and +1 AC or something, add an extra d6 and armor boost per teir, by L17 itll be +3 AC an 3d6 extra radiant, but I am afraid that might be too good for something he bought and didnt even do anything to get.

How should my players realize they misidentified an item?

One of my players misidentified a Pendant of the Occult. I told him it gives the +1 to Occultism checks, but also told him it can be used on a target to give a -1 status penalty to their next attack roll, Perception check, saving throw, or skill check (basically reverse-Guidance).

I immediately realized I didn’t make the effect obvious enough, so the players probably won’t notice that the Pendant is having the opposite effect unless I add some sort of descriptive flourish to make the effect blatant.

Is that what I should do, or is there any rules guidance about how (or when) PCs should realize their misidentification?

Workshopping issues with proposed item: Timelocked Breadbox

I’m considering putting a homebrewed piece of treasure into my game (5e Exandria campaign). Specifically, it is a box, approximately the size of a breadbox. Time does not pass inside the box while the lid is shut. If the box is broken, the enchantment is lost. If a portal to an extradimensional space is placed into the box, such as a bag of holding, the interior of the extradimensional space is not affected, but anything inside such a space would be unable to leave while the box is shut.

My question is this: What potential issues or cheese might result from this item that I haven’t yet thought of? The party is currently lvl5.

Which magic item of very rare or lower rarity is most useful to protect a group of ordinary soldiers?


Background

I’m playing a mid-level artificer (artillerist) who’s a disgruntled veteran with a missing limb who, disillusioned by the leaders’ willingness to send soldiers to their deaths, has retired from the army and opened a shop. An adventure hook has people steal his work-in-progress masterpiece and now I need to find a fitting item he was trying to create.
Because of this background, the item he would be most interested in would be something that helps ordinary soldiers without magic powers survive the horrors of the battlefield. It might be something that protects a group of people from hostile spells or something that provides healing to them, similar to the artificer’s Protector cannon.

Criteria

  • I am trying to find an officially published item before resorting to homebrew (UA is probably fine, as is basic refluffing)
  • The DM has ruled that the item should be below legendary rank, so very rare at most
  • I probably won’t be held to strict prerequisites such as being able to cast every spell going into the items myself, but the item should still basically fit the artificer flavour
  • The item should be usable by someone who cannot cast spells
  • The item should be able to affect a group, not just the carrier
  • The item should be defensive in nature

My own research

I’ve gone through the "warding" and "healing" categories of magic items on D&D Beyond and found very little. There are almost no items that work on groups and those that do tend to be musical instruments or magic staves that need the user to be a spellcaster.
In general it seems that antimagic items aren’t really a thing in 5e. An item that can cast Antimagic Field on he regular would probably be in the legendary category and a Ring of spell Storing would again require a (powerful) spellcaster to be useful.
An ideal solution would be something like a banner of protection or an Eldritch Cannon: Protector that doesn’t need an artificer to be present. I’ve also considered something like a Ring of Regeneration, but that’s again a one-person item.

Can an artificer replicate the same magic item more than once?

Artificers can take the "Replace Magic Item" infusion more than once, each time choosing a magic item that they can make with it.

Can an Artificer take the "Replace Magic Item" infusion multiple times and select the same magic item with it, and thus create more than one copy of the same magic item?

For example, could a level 2 Artificer take "Replicate Magic Item: Bag of Holding" for 2 of its 4 known infusions, potentially creating 2 Bags of Holding at the same time?