Does changing the outside dimensions of a Bag of Holding break anything mechanically?

One of my players made a character who's a 2ft. tall gnome artificer. He just created a bag of holding as his wondrous invention, but the exterior dimensions (2ft. wide by 4ft. deep) is bigger than him. So I decide to make it a drawstring backpack with a 2ft. mouth so he still has the same insertion dimensions, and 1.5ft. deep so he can wear it like a backpack and not trip.

Does this change anything about the bag mechanically? Does this seem like a reasonable change?

1 Answer

Bag of Holding states:

If the bag is overloaded, pierced, or torn; it ruptures, is destroyed, and its contents are scattered in the Astral Plane...Placing a bag of holding inside an extradimensional space created by a Handy Haversack, Portable Hole, or similar item instantly destroys both items and opens a gate to the Astral Plane. (DMG 173-174)

This suggest that the interior of the bag is a confined space/pocket dimention within the astral plane and the mouth of the bag is in essence a portal to this space. Thus, it should not be affected by the outside dimensions on the material plane.

Related answer

• The space is a pocket dimension within the astral plane but otherwise great answer. – David Coffron Jun 23 '18 at 16:03
• @DavidCoffron -- do you have a citation I can add? – ravery Jun 23 '18 at 16:12
• This answer discusses the equivalency of extradimensional spaces and demiplanes and all demiplanes exist within the astral sea (the transitive planes, including the astral plane connect the planes within the astral sea, see DMG section on the planes) – David Coffron Jun 23 '18 at 17:07
• I suppose it doesnt explicitly say the plane is within the astral one, but the bit on how it gets spilled into it led me to believe that was the case. Demiplanes follow their own rules (PHB) so it could just be 'a plane in the astral sea that happens to spill into the Astral Plane when it bursts' – David Coffron Jun 23 '18 at 17:10
• @DavidCoffron -- Thanks, I added a link to the related answer – ravery Jun 23 '18 at 17:12