What's the dispel DC for a spell made permanent by another caster?

Question

I am level 9 and I cast an Enlarge Person spell on myself.

An NPC is level 16 and casts Permanency on that Enlarge Person effect to make me larger permanently.

When an enemy later attempts to dispel the Enlarge Person effect, does the enemy roll against the caster level of me as the caster of Enlarge Person or the NPC's as the caster of Permanency?

Answer 1

When the dispel magic spell's caster attempts to dispel the question's enlarge person spell, the caster makes a caster level check (DC 20; i.e. DC = 11 + the caster level of the enlarge person spell). If the caster succeeds, the dispel magic spell dispels the target's enlarge person spell. If the caster fails, the enlarge person spell remains. To be clear, this occurs whether or not a permanency spell has been applied to the enlarge person spell; the permanency spell is a non-issue here.

All the spell permanency does is change a spell's duration from its printed duration to permanent (therefore the spell continues forevermore until dispelled or suppressed). That is, while the permanency spell has the entry Duration: Permanent; see text, the text that should be seen is this: "This spell makes the duration of certain other spells permanent. You first cast the desired spell and then follow it with the permanency spell."

Thus the caster of a dispel magic spell can affect a spell modified by a permanency spell but can't affect the permanency spell itself. (This gives the actual permanency spell essentially a duration that's sort of instantaneous—one casting of the spell permanency changes forevermore the duration of that specific casting of the target spell until that specific casting of that spell is dispelled.)

So it usually doesn't matter at what caster level the permanency spell is cast. (See below for a noteworthy exception.) The spell permanency still requires a minimum caster level to target some spells, of course, but nothing remains of a permanency spell after it's cast. It did its job by changing the target spell's duration, and now to get rid of the spell the changed spell must be dispelled. There simply is no ongoing permanency spell to be dispelled separately.

Typically, the only thing that alters the difficulty of dispelling a spell affected by the permanency spell even a little is if a caster casts permanency on a spell he cast on himself that's also on the chart that's labeled Target: Self Only in the permanency spell description. In that case, not only must the dispel magic spell's caster succeed on a caster level check (DC = 11 + caster level of the changed spell) but also the spell changed by the permanency spell "can be dispelled only by a caster of higher level than you were when you cast the spell." (N.b. Here the spell means the spell on the Target: Self Only list and, again, not the permanency spell!)

In other words, a caster can cast on himself a spell from the chart Target: Self Only and make it permanent on himself with the permanency spell and know that only a caster that possesses a higher level than he was when he cast the spell on the chart can dispel that spell. (Here higher level probably means high caster level, but ask the GM.) By the way, sadly absent from the Target: Self Only chart is the spell enlarge person.

Answer 2

Foreword

I think that @HeyICanChan's response is a perfectly reasonable RAI interpretation of permanency, and I would have no complaint about a GM using it in a game in which I played. However, I think that, RAW, the spell functions a little differently...

Text of the Spell

The permanency spell reads as follows. I've highlighted the sections that are particularly important to my understanding of how it works:

School universal; Level sorcerer/wizard 5; Domain [subdomain] Magic [rites] 5

CASTING

Casting Time 2 rounds Components V, S, M (see tables below)

EFFECT

Range see text

Target see text

Duration permanent; see text

Saving Throw none; Spell Resistance no

DESCRIPTION

This spell makes the duration of certain other spells permanent. You first cast the desired spell and then follow it with the permanency spell.

Depending on the spell, you must be of a minimum caster level and must expend a specific gp value of diamond dust as a material component.

You can make the following spells permanent in regard to yourself. You cannot cast these spells on other creatures. This application of permanency can be dispelled only by a caster of higher level than you were when you cast the spell.

...

In addition to personal use, permanency can be used to make the following spells permanent on yourself, another creature, or an object (as appropriate):

...

Additionally, the following spells can be cast upon objects or areas only and rendered permanent:

...

Spells cast on other targets are vulnerable to dispel magic as normal. The GM may allow other spells to be made permanent.

From the text, it seems clear that permanency is intended to work differently depending on whether it's cast on one of the personal-only spells or on one of the other spells. We need to consider both cases.

Personal-Only

What The Rules Say

The phrasing of "This application of permanency can be dispelled only by a caster of higher level than you were when you cast the spell" seems to indicate that it's the permanency spell being dispelled here. That's consistent with the spell's duration being "permanent" instead of "instantaneous":

Instantaneous: The spell energy comes and goes the instant the spell is cast, though the consequences might be long-lasting.

Permanent: The energy remains as long as the effect does. This means the spell is vulnerable to dispel magic.

Permanency has a duration of "permanent", which indicates that the spell's magic continues working indefinitely. This is similar to spells like baleful polymorph, which doesn't wear off on its own but can be dispelled. If the subject of baleful polymorph walks into an anti-magic field, they revert to their normal shape while they're inside.

On the other hand, a spell like feeblemind has a duration of "instantaneous" - it does its damage and then the spell dissipates. The effects of feeblemind can only be removed by specific spells like heal and limited wish. Dispel magic has no effect because nothing stays around to dispel, and a feebleminded person who walks into an anti-magic field is still feebleminded while inside.

This all suggests that if you scan a person with permanent see invisibility, you see two magical auras - one for see invisibility and one for permanency. This, in turn, suggests that since dispel magic removes a single spell, it can potentially remove either see invisibility or permanency.

What Does Dispelling Permanency Mean?

The spell doesn't explain what dispelling permanency means, but two reasonable interpretations are:

1. When permanency is cast, the target spell's normal duration is paused. When permanency is dispelled, the target spell continues for whatever is left of its normal duration.
2. Time under permanency counts against the spell's duration normally, just like when a spell is suppressed by anti-magic field. Usually, the target spell will already have exceeded its duration and will end immediately.

Dispelling the Target Spell

What if the spell targeted with permanency is dispelled? Again, the text doesn't specify, but I can think of two possible interpretations:

1. With its target gone, the permanency spell vanishes. This is how I would usually rule it.
2. The permanency spell no longer has any effect, but it still exists and could support another casting of the same spell (since the cost of permanency varies by spell, it wouldn't support the casting of any spell that can be made permanent). This would allow the caster to restore the permanency of the spell without spending the cost again. I might use this interpretation in a low-money game to avoid screwing a PC, or when an evil wizard escapes and comes back for revenge.