When the permanency spell was cast we used to have the Wizard roll a con save. On a fail they lose a con point for a year.
A wish spell could bring it back right away but the wish spell had the same con limitations.
On any con fail the spell obviously failed also.
As for creating magic items we had a few rules to limit things also. When creating any item with charges each charge required a spell for the effect AND the permanency spell. Thus a wand of lightning with three possible charges a day would need three lightning spells plus three permanency spells cast on it during creation. Any failure would stop the creation process at that point. Thus you might have planned on creating three charges but the second permanency spell failed so you only got a one charge wand.
It quickly limited the amount of stuff a wizard was willing to make.
I see no reason why enlarging a portable hole wouldn't work exactly as written, doubling the size of each dimension. Even if you want to get ticky-tacky over whether the entrance is targetable when it's unfolded, it would surely be affected if you target someone carrying it.
The permanency discussion is a bit old, but it's also a little off. For reference: In 1st Edition only a few, specific spells could be made permanent on a living target (no perma-haste, sorry) and it cost the caster a point of constitution forever. When using permanency to complete a magic item, the wizard instead had a 5% chance to permanently lose a point of con.
In 2nd, permanency had three lists of spells. One of spells the caster could make permanent on themselves, one they could use on other creatures or objects, and one for objects only (it encouraged DMs to consider allowing other spells). Choosing any of these lower the user's con by a point. It was also used to finalize magic items made with the enchant an item spell, with a 5% chance to drain a point of constitution. Whether "draining" is different from "lowering" was a good way to get an argument going - I personally allowed restoration of drained, but not lowered, con. Otherwise nobody would create magic items except the most ridiculously powerful ones, and only for themselves.
2e suggested that the spell may expire after a thousand years, presumably because the designers were doing a lot of cocaine back then and had to write down every little thought that crossed their mind, but nobody used that rule. Why would they? Both editions left open the question of whether a wizard recovered their constitution if the permanency was dispelled (or, I suppose, expired). This was a question nobody thought about until it came up, at which point friendships were tested.
That said, if I were making a permanency spell for 5e, I'd probably ditch all of its baggage and have it use attunement slots as a limiting factor. Maybe limit it to 2nd-level or lower spells on creatures and some other level on objects? I personally would not require it for general magic item creation.
When the permanency spell was cast we used to have the Wizard roll a con save. On a fail they lose a con point for a year.
A wish spell could bring it back right away but the wish spell had the same con limitations.
On any con fail the spell obviously failed also.
As for creating magic items we had a few rules to limit things also.
When creating any item with charges each charge required a spell for the effect AND the permanency spell.
Thus a wand of lightning with three possible charges a day would need three lightning spells plus three permanency spells cast on it during creation. Any failure would stop the creation process at that point. Thus you might have planned on creating three charges but the second permanency spell failed so you only got a one charge wand.
It quickly limited the amount of stuff a wizard was willing to make.
I see no reason why enlarging a portable hole wouldn't work exactly as written, doubling the size of each dimension. Even if you want to get ticky-tacky over whether the entrance is targetable when it's unfolded, it would surely be affected if you target someone carrying it.
The permanency discussion is a bit old, but it's also a little off. For reference: In 1st Edition only a few, specific spells could be made permanent on a living target (no perma-haste, sorry) and it cost the caster a point of constitution forever. When using permanency to complete a magic item, the wizard instead had a 5% chance to permanently lose a point of con.
In 2nd, permanency had three lists of spells. One of spells the caster could make permanent on themselves, one they could use on other creatures or objects, and one for objects only (it encouraged DMs to consider allowing other spells). Choosing any of these lower the user's con by a point. It was also used to finalize magic items made with the enchant an item spell, with a 5% chance to drain a point of constitution. Whether "draining" is different from "lowering" was a good way to get an argument going - I personally allowed restoration of drained, but not lowered, con. Otherwise nobody would create magic items except the most ridiculously powerful ones, and only for themselves.
2e suggested that the spell may expire after a thousand years, presumably because the designers were doing a lot of cocaine back then and had to write down every little thought that crossed their mind, but nobody used that rule. Why would they? Both editions left open the question of whether a wizard recovered their constitution if the permanency was dispelled (or, I suppose, expired). This was a question nobody thought about until it came up, at which point friendships were tested.
That said, if I were making a permanency spell for 5e, I'd probably ditch all of its baggage and have it use attunement slots as a limiting factor. Maybe limit it to 2nd-level or lower spells on creatures and some other level on objects? I personally would not require it for general magic item creation.
Oh we are attempting to put a dragon inside the portable hole, then throw a bag of holding in there to cause the astral gateway banish effect.
The bag just needs to enter the hole and EVERYTHING inside 10 ft gets dragged into another plane.
Just open the hole on the ground and when the dragon gets over the hole throw the bag in.
Or open it on a wall and using an illusion trick him into sticking his head into it then toss in the bag.