What is the mechanism for a character swapping their arcane/Druidic focus

Question

As has been pointed out, a Druidic focus and a holy symbol are distinct from an arcane focus, but given they all perform essentially the same function, and the same issues probably apply to all of them, I’m going to leave this question broad to apply to all foci.

At the core, I believe my questions are:

• is a focus any item of a suitable class (staff, wand, etc) which the caster is somehow “attuned to” (in the general sense, not the 5e mechanics sense), or is it a specific property of certain specific items (ie a staff must be specifically manufactured as a focus to be one)?
• if only certain items can be a focus, is there any mechanism to make an item into a focus (e.g. similar to how a weapon can be silvered)

Details for my specific issues:

One of my players (Druid) started at L1 with a Druidic focus (staff). Later they picked up a better staff (staff of bird calls), with some magic capabilities. Can they use the magic staff as their Druidic focus, or do they have to carry around their starting staff forever?

Similarly I have a sorcerer who’s picked up a staff of defence. Does he need to hold both staves to use the staff of defence’s capabilities and to cast magic using his arcane focus staff, or can he somehow designate / transfer the focus to the staff of defence?

I’m going to have a similar issue with a paladin player who has their Holy Symbol on their shield, as soon as they find a +1 shield. Will they have to choose between using the +1 shield for the AC bonus and their original shield to be able to cast? Or can they ‘swap’ the holy symbol onto the new shield? Would this require a blacksmith or a ceremony or something?

Answer 1

- is a focus any item of a suitable class (staff, wand, etc) which the caster is somehow “attuned to” (in the general sense, not the 5e mechanics sense), or is it a specific property of certain specific items (ie a staff must be specifically manufactured as a focus to be one)?

In the PHB (and Basic Rules), the description of arcane focus items says:

An arcane focus is a special item — an orb, a crystal, a rod, a specially constructed staff, a wand-like length of wood, or some similar item — designed to channel the power of arcane spells.

Jeremy Crawford was asked on twitter:

Q: Can a wizard use a magic wand (e.g. wand of Magic Missile) as her arcane focus?
A: Yes.

Trying to reason out his conclusion, we can assume that is because a wand that casts spells is "a wand-like length of wood... designed to channel the power of arcane spells".

It seems fair to apply the same to magic staffs. If you wanted to split hairs, you could say that only staffs that cast spells are capable of being used as an arcane focus. Or you could be lenient and say that all magic staffs can.

A druidic focus is harder to substitute.

A druidic focus might be a sprig of mistletoe or holly, a wand or scepter made of yew or another special wood, a staff drawn whole out of a living tree, or a totem object incorporating feathers, fur, bones, and teeth from sacred animals.

Any wand that is not described otherwise could be assumed to be "made of yew or another special wood", but it is unlikely that your average staff was "drawn whole out of a living tree".

(A lenient DM may allow any nature-related staff to be used as a druidic focus, but this is not going strictly by the books.)

And it is also possible for a wand (and maybe a staff) to qualify as both Arcane and Druidic focus.

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- if only certain items can be a focus, is there any mechanism to make an item into a focus (e.g. similar to how a weapon can be silvered)

So far, there are no rules detailing specifically how a focus item is created. But there are general rules for crafting mundane and magical items.

In the case of a shield holy symbol, "A holy symbol ... might be an amulet depicting a symbol representing a deity, the same symbol carefully engraved or inlaid as an emblem on a shield, or a tiny box holding a fragment of a sacred relic." Presumably, a player could ask someone with the right skills to engrave or inlay their holy emblem on their shield. I assume the cost would be the listed cost for buying a holy symbol.

Answer 2

There are no mechanics for swapping focuses.

If the two items you have are both appropriate focuses, then the caster need only pick up and start using the new one. There are no rules about not being able to swap focuses. For example, the only rule druids have about using a Druidic focus is:

You can use a druidic focus (see the Adventuring Gear section) as a spellcasting focus for your druid spells.

To make use of a new focus, a caster need only pick it up.

Druids must use a Druidic focus.

An arcane focus and a Druidic focus are two different items that are not interchangeable. An arcane focus is defined:

An arcane focus is a special item--an orb, a crystal, a rod, a specially constructed staff, a wand-like length of wood, or some similar item--designed to channel the power of arcane spells. A sorcerer, warlock, or wizard can use such an item as a spellcasting focus.

Whereas a Druidic focus is:

A druidic focus might be a sprig of mistletoe or holly, a wand or scepter made of yew or another special wood, a staff drawn whole out of a living tree, or a totem object incorporating feathers, fur, bones, and teeth from sacred animals. A druid can use such an object as a spellcasting focus.

Each type of focus is specifically designed to be the type of focus that it is, and they are not the same thing. If the particular item is explicitly called an arcane focus, the Druid cannot use it as a focus for their Druid spells.

Answer 3

A few things:

Different casters have different focuses. Druids use a Druid Focus, Wizards and Sorcerers use Arcane Focus, and so forth.

A character is not tied or attuned to any particular focus. A Wizard can start with their quarterstaff and later pick up a perfectly good wand and be happy. They can even lose both and just use material components if a focus is no longer available.

Now with the Paladin and his shield, you're talking about Holy Symbols, specifically, an Emblem. You would have to work with your DM with regards to transferring it across. Generally, the emblem would be permanently affixed (or else risk having it fall off or other issue).

So characters can switch some focuses without issue, others not so much.

Answer 4

A "druidic focus (wooden staff)" is not just a hunk of wood. It's an expensive, special-purpose hunk of wood. Not every staff is a druidic focus, else a 2-sp quarterstaff could replace this 5-gp piece of gear. If a piece of equipment does not say that it is a druidic focus, it is not one.

Neither the staff of bird calls nor the staff of defense state that they can be used as magical foci of any sort, so whether a spellcaster is permanently committed to a particular focus is irrelevant. Neither does a +1 shield have such a property.

However, neither is there any rule that says that you can only ever use the same object as a focus. A spellcaster might carry multiple foci from the very beginning.* And when they find an object that they would rather use as a weapon** or shield than their original focus, they can obtain a different focus and use it going forward.

There is no mechanism for making an arbitrary item into a focus. The closest the rules come is letting one inscribe a holy emblem on another item. This doesn't make that item into the focus, but it means one can be holding both the item and the focus with the same hand.

*: There's no rules reason to do this, but that doesn't mean you can't do it. One of my wizard PCs uses different foci for different sorts of spells. It's yummy flavor.

**: A staff-shaped focus isn't even a weapon, though it likely can be treated as an improvised weapon that works just like a quarterstaff.

Answer 5

Focus objects are expensive

Most cost 5 gold pieces, some cost 10 gold pieces. They are not just "a bit of wood ripped from a tree" or "a lump of cystal."

In particular, a staff weapon is only 4% of the cost of an arcane focus staff (2sp vs 5gp).

This implies they must be specifically manufactured as a focus item.

Perhaps they are intricately made (a 5 gp object takes a full day to craft)? Perhaps they are made of special, magic-affecting materials? The book doesn't say.

The book doesn't even say what sort of crafter makes them. Can a wizard make their own rod or wand, or do they require Jewellers' Tools proficiency?

Focus objects don't require attunement

A focus object is not a magical item.

Any arcane caster can pick up any arcane focus, even one belonging to another caster, and use it.

Some magic items are a focus item; some are not

For example, the Tome of the Stilled Tongue says, "If you can attune to this item, you can use it as a spellbook and an arcane focus."

The DMG does not say if magic staves, rods and wands count as arcane focus staves rods or wands, or not. I have gamed with GMs who ruled both options. Expect table variation.

Answer 6

Attunement?

You ask:

is a focus any item of a suitable class (staff, wand, etc) which the caster is somehow “attuned to” (in the general sense, not the 5e mechanics sense)...?

Why do you believe this (weak) attunement is required? PHB chapter 5 says about druidic foci (with similar wording for arcane foci):

A druidic focus might be a sprig of mistletoe or holly, a wand or scepter made of yew or another special wood, a staff drawn whole out of a living tree, or a totem object incorporating feathers, fur, bones, and teeth from sacred animals. A druid can use such an object as a spellcasting focus, as described in chapter 10.

Nothing about attunement being required in the item description. Perhaps chapter 10 (spellcasting) mentions it in its section on foci - but they're only mentioned twice there:

A character can use a ... spellcasting focus ... in place of the components specified for a spell.

A spellcaster must have a hand free to ... hold a spellcasting focus — but it can be the same hand that he or she uses to perform somatic components.

Conclusion

I don't see any requirement for attunement here. Foci are just equipment that do something (eliminate material component requirements) when held. Spellcasters should be able to pick up any focus they find (and are proficient with) and immediately use it as a focus, just as martial characters can pick up any sword they find and immediately use it as a sword.