Defence against the Dark Arts [not Harry Potter]

[JellyPooga]

So I'm just about to be starting in on an Evil campaign and have decided to go with the Dark Knight stereotype; black, spiky armour, weird looking sword, horse with red eyes...you know, the works. At least eventually. For now he's just a Half-Orc ex-cavalryman with a mean streak.

Anyway, as I was building the character, I realised that his Wisdom was never going to be great and he won't be picking up Wis Save proficiency at any point, making him particularly susceptible to some of the nastier magic out there; Hold Person, Charm/Dominate and so forth. Then it occurred to me...

A character cannot be affected by the same ongoing effect multiple times.

With other, (apparently) friendly casters in the party, would it be a viable defence against enemy spellslingers looking to hijack my beefcake tank, to have a friendly cast some such spells on me in advance, ensuring my mental protection?

This obviously won't work for the likes of Hold Person (Paralyzed is Paralyzed, after all), but having immunity to Charm Person, Suggestion, Dominate Personand...well that's probably about it...because you're already Charmed/Dominated/Suggested by a friendly (who obviously won't abuse the trust in submitting yourself to such a spell :smallamused:) is somewhat easier than getting hold of a Mind Blank effect or immunity to Charm (when you're not a Paladin or friends with one, I guess).

So, does this work or am I misunderstanding the Combining Magical Effects rules on pg.205?

[Giant2005]

It works, but I sure wouldn't want to rely on it - it is too far in the realm of DM interpretation.
Basically, the DM gets to decide which spell is more potent. A strong argument could be made that the Charm Person that is just sitting there essentially doing nothing, is much less potent than the one that would compel you to go against everything you believe in.

[Pazerniusz]

To be honest it is kinda grey arena, no example for many charm-like spells on one person isn't helpfull at all.
In my group we do higher level spell override lower, same level are spellcasting ability contest, but rules is even stated stronger effect override weaker. Durations only overlaps if allies cast exactly this same spell.

C o m b i n i n g M a g i c a l E f f e c t s

The effects of different spells add together while

the durations of those spells overlap. The effects of

the same spell cast multiple times don't combine,

however. Instead, the most potent effect—such as the

highest bonus—from those castings applies while their

durations overlap.

For example, if two clerics cast bless on the same

target, that character gains the spell’s benefit only

once; he or she doesn’t get to roll two bonus dice. PHB 205
Maybe in some eratas is clarification.

[JellyPooga]

A strong argument could be made that the Charm Person that is just sitting there essentially doing nothing, is much less potent than the one that would compel you to go against everything you believe in.

On the flipside, the argument could be made that a Charm cast by someone you already have trust with is only reinforcing the potency, as compared to a Charm that is attempting to make you go against your natural instincts.

It's easier to make a ball roll downhill than up.