Uncancellable spells

[Tor]

The magic writeups in most main books I have read indicate that spellcasters can usually cancel any spell they cast at will. I am wondering if we could work on compiling a list of exceptions to this.

One that comes to mind is the spell Transferal. It mentions in that case, to get your PPE and spellcasting abilities back from whoever you hide them in, that you must wait for the duration to end or touch the person. While it could've been more explicit, the strong indication here is that you can't simply cancel the spell, or at least if you do, you can't get your PPE back.

It makes me wonder, what happens if a spellcaster tries to cancel it, or it is cancelled by some other means, like a 'negate magic' or 'anti-magic cloud'. I'm not sure if a Nega-Psychic or Psi-Nullifier or Sea Inquisitor or Guardian or Phase Mystic could interfere with it once it's in effect.

Rather than something extreme like 'you never get your spellcasting back', I figure a reasonable solution is if the duration doesn't expire normally or you don't touch the person, the PPE in them disappates. The person should probably get their powers back but should probably have to wait for the duration to expire before they return in full (past 1st level proficiency).

Regarding the duration, I assume that's something fixed once you choose what it is upon casting, and that a higher-level cast could opt to set a lower duration if they wish.

What other spells do you think could not simply be ended at a whim? Perhaps things like Mummy/Golem/Zombie or summoned Shadow Beasts or demons? I get the impression from most 'instant' spells like healing/damage that you can't 'cancel' them either, by their nature, so I guess the focus should be on those with ongoing durations which would not be cancellable.

[Nekira Sudacne]

Summoning spells can't be canceled persay, but you can always order the demon/elemental/whatever to return to hell before the duration expires which has the effect of ending the spell, and you can also set conditional orders to that effect, such as "return to your home plane if you are greviously injured/as the sun starts to rise" are examples of valid conditional cancelations.

Now if you forget to set conditional "return" orders and you are prevented from giving further orders then the spell is uncancelable.

[drewkitty ~..~]

There is item in the magic Proficiencies & Limitations in one of the rifters that is called "Unstoppable spells".

[Rimmerdal]

Most spell with a duration longer that 'instant' or 'None' is probably is able to be canceled. This could prove to be a good interrogation trick. Web....er CoA a guy to a surface and put him over a large drop...then well you get the picture.

Summons once they end may allow an end early..but make sure the subject is not going to be hostile or die immediately. Also if the summon stays and likes the place you could well have a problem getting rid of them if cancel your summons,

[Glistam]

At a quick look, these were the only invocations I noted in the Rifts: Book of Magic that could not be cancelled early:

Instill Knowledge
Luck Curse
Summon Shadow Beast (once it breaks free of the Mage's control)