In 4th Edition, there was an Permananet / Instant duration that a spell could be extended to.

In the 5th Edition, is there a way to make a spell permanent?

For instance, the ritual spell The Chirurgeon's Touch, uses vis to turn a Momentary effect (healing a light wound) into a permament, mundane effect.

However, is there a way to create an enduring (i.e. longer than a Year) magical effect (say, a glowing tree or a permanent water spout) that does not involve enchanting an item.

If so, can this be applied to Formulaic or Spontaneous spells in any way?

Thanks.

Enduring magical effects are the province of magical items, not spells in 5ed.

Good to have that clarification. Thank you.

Can you further clarify about Momentary duration spells.

Can only Creo spells be made permanent with vis - creating mundane artifacts, plants, or animals?

Are there other Techniques or Forms that this also applies to?

Is the expenditure of vis required simply the 1 per magnitude of the spell?

Can non-ritual spells (formulaic, spontaneous) be converted from Momentary into "permanently mundane"?

Thanks.

Plenty of spells have a permanent duration with the Momentary duration. For example, Rego Animal, use it to teleport a dog from one place to another. The magic comes and goes, but the dog stays in his new location. The magic is gone, but the effects remain. A Perdo Terram will destroy the rock, and it won't come back. The only thing that doesn't really do that is Muto. With Muto, when the duration ends, the target reverts back to what it was, and that duration can be no longer than Year (as a Ritual).

In the new system, there is no way to use Vis in the field for a longer duration or range. Instead of that, spells that created something permanent or repaired it permanently are Rituals now. Non ritual spells cannot be converted in such a way. You can make a non ritual Creo Corpus healing spell, but as soon as it ends, the wound returns.

Basically with Momentary duration, the effect comes and goes, the target's state depends (usually) on the technique used. Muto means they return immediately. Most others mean the intended effects stay (a flash of flame ignites stuff). If you want to make things permanent (a permanently floating carriage) then you need to enchant the carriage, not create a spell.

One last question in this vein.

--Instead of that, spells that created something permanent or repaired it permanently are Rituals now--

Must Ritual spells be invented or learned from lab texts? Can they be created at need (in less than a season)?

Is there any way to, for instance, cast a spontaneous healing spell (Creo Corpus) and make the effects permanent by casting it with Ceremonial Magic?

Not trying to be thick headed about this. Your explanations have been very clear. I just want to confirm that I have not missed something in regards to how Ritual spells are defined. Thanks.

For your consideration - a summary (liberally plagerized from the generous posters above). I need to present my players with a good explanation of this behavior. Please let me know if you think this details the main points at issue in a clear fashion. I welcome suggestions on how to improve it (or tricky areas / boundary conditions).

A Clarification of Enduring Magical and Non-Magical Effects in Ars Magica 5th Edition

The longest duration that a Formulaic or Spontaneous spell may have is Moon/Ring.

The longest duration that a unnatural effect may have is Year (unless enchanted into an item). Only Ritual spells may have a duration of Year. Rituals spells must be learned / invented like Formulaic spells. They cannot be constructed at will like Spontaneous spells. An unnatural effect persists magically and can be dispelled / destroyed with magic (Perdo Vim) before its normal expiration time.

Examples:
If Muto Corpus is used to change a man into a frog, the effect persists only as long as the spell's duration. The maximum this could be is Year, with a Ritual spell (unless the effect was produced by an enchanted ring the man was wearing). As long as the spell lasts, the magic perists. If a Perdo Vim spell overcomes the magic affecting the man, he will revert to his normal shape.

Many spells, of all types, can produce natural effects. Natural effects, once achieved, cannot be dispelled / destroyed with Perdo Vim (but obviously the target could be re-affected by new magic that might undo the natural effect).

Assuming a natural effect is being produced, a Momentary duration is ususually sufficient to cause the effect to persist indefinitely.

Examples:
If Rego Animal is used to teleport a dog from one place to another, it achieves the effect within the Momentary duration and, after expiring, the dog remains in the new location. The magic has expired but the effect has not.
If Perdo Terram is used destroy a rock, the rock will not reform afterwards.
If Intellego Aquam is used to discern the location of a sunken ship, the knowledge produced within the mind of the magus persists normally, and is not forgotten when the spell expires.
If Creo Ignem is used to produce a magical spark with a duration of Momentary, when the spell expires the spark will disappear. But non-magical tinder ignited by the spark would continue to burn.

Vis cannot be used to extend the range, target, or duration of a spell. Instead, spells that create something permanent or repair it permanently are Rituals now, and require the use of Vis (1 pawn per magnitude). Non-ritual spells cannot be converted in such a way. You can make a non ritual Creo Corpus healing spell, but as soon as it ends, the wound returns.

To my understanding, minor effects such as a glowing tree or a continuous water spout can have permanent durations (sans magical items)
as long as said spells are written as rituals AND does not violate the essencial nature of the target. For example, a glowing tree can be permanent if the glow is caused by something natural, like the constant presence of fireflies. The tree would still be subject to natural aging, tho. A continuous waterspout can be made permanent, as long as it was in an area where water was naturally available, tho the strength of it's flow may be subject to seasons of flood or drought.

Rule of thumb: (but not law)
Creo - always
Intelligo - sometimes
Muto - never
Perdo - always
Rego - sometimes