Do infused items retain their original properties, or use those of the magic item?

[Greywander]

This came up in a session today. We recently hit 2nd level, so I grabbed the Bag of Holding infusion. A sack normally weighs half a pound, but a bag of holding weighs 15 lbs. We weren't sure whether the infused sack should retain it's own weight, or assume the weight of the bag of holding. DM ruled that the bag of holding weighing 15 lbs. is a property of the magic, so the sack would weigh 15 lbs. too.

This also leads into a broader question of whether an infused item could be better (or worse) than the magic item the infusion is based off of. For example, using a sack or other container with an opening that is larger than what a bag of holding normally has, allowing you to fit items inside that would normally be too big to fit through the aperture in a bag of holding.

[Mastikator]

Whenever you finish a long rest, you can touch a nonmagical object and imbue it with one of your artificer infusions, turning it into a magic item. An infusion works on only certain kinds of objects, as specified in the infusion's description. If the item requires attunement, you can attune yourself to it the instant you infuse the item. If you decide to attune to the item later, you must do so using the normal process for attunement (see the attunement rules in the Dungeon Master's Guide).

You can't infuse a magic item.

[PhoenixPhyre]

You can't infuse a magic item.

That's not the issue here. It's that some non-magical host items have different properties (weight, size, etc) from the infused magic item.

My ruling--you get the magic item properties. I'm not going to try to tease out which ones you keep and which ones you don't. If there's a conflict, the infusion takes priority.

[Kane0]

My ruling--you get the magic item properties. I'm not going to try to tease out which ones you keep and which ones you don't. If there's a conflict, the infusion takes priority.

For ease of play i’d agree with this.

If you’re super into the magic item creation thing I’d put more effort as DM into figuring exactly how your artificer infusions work in relation to the items they come from and probably end up with more in depth crafting magic item stuff, but thats specific to the player being into all that.

[MoiMagnus]

I find it dubious that the bag change weight, however:

(1) I'm totally fine with the infusion only being valid on a 15lbs bag. I mean, you would reject "bag of holding" being used on a sword, because a sword is obviously not a bag, so there are some limitation on what is a valid target for the infusion. Weight and dimensions could be part of those limitations.

(2) I'm totally fine with having bag of holdings of different weight (even on the market). I don't think magic items are mass produced, so they should all have small differences in properties. 15 lbs is the usual weight, but weight might vary depending on who created the bag.
(Using a magic item that significantly deviate from the norm, like a 1lb bag of holding, might result in some unexpected issues, like spontaneous rupture of the bag. There is probably a reason why most bags of holding are around 15 lbs.)

[Sigreid]

If you read the description of the bag of holding, it's not so much a sack (1lb) and more a sea bag. It's pretty huge. I would assume the infusion would make the bag grow to meet that physical dimension as well.

[quindraco]

This came up in a session today. We recently hit 2nd level, so I grabbed the Bag of Holding infusion. A sack normally weighs half a pound, but a bag of holding weighs 15 lbs. We weren't sure whether the infused sack should retain it's own weight, or assume the weight of the bag of holding. DM ruled that the bag of holding weighing 15 lbs. is a property of the magic, so the sack would weigh 15 lbs. too.

This also leads into a broader question of whether an infused item could be better (or worse) than the magic item the infusion is based off of. For example, using a sack or other container with an opening that is larger than what a bag of holding normally has, allowing you to fit items inside that would normally be too big to fit through the aperture in a bag of holding.

I agree with your DM. Post-infusion, your item must match everything in the magic item's description, but anything not mentioned is fair game. Anything in the description should be treated as mandatory, and part of the infusion process.

[Greywander]

Anything in the description should be treated as mandatory, and part of the infusion process.
This actually makes the most sense. Simple and straightforward.

Beyond that, I'm not sure what the limits are for infusing a bag of holding. I think potentially any container could be infused, even something like a tankard or vial. The downside of containers like those could be things like the opening size (you're not stuffing a ladder into a tankard or vial) and a lack of ability to close the container (careful you don't turn that tankard upside-down). You might be able to have an item custom-made for infusing, such as a bag that is easily carriable, has a large opening, can be fastened shut, and is pretty small and unobtrusive (so, probably something like an actual bag of holding).

[Orsyn]

It weighs 15lbs and can hold 500lbs or 64 cubic feet of stuff. Anything beyond that I'm not splitting hairs over, especially not when artificers are called out in a sidebar to fluff their magic appropriately.

If you wanna explain to me that your magicked inkwell dissolves things into component particles and suspend them in ectoplasmic fluid to share the burden with the astral plane, or that the runes on the neck glow and it just kinda pythons the ladder into itself, I'm not going to fight you on it tbh.

[Ogun]

I like idea of a "bag" that disassembles items into component parts, then reassembles them as they are pulled out.
I also like the idea of a 4" scabbard swallowing a 24" sword