Effect for a Mage Slayer type function

[Klandare]

I am looking to make a new magic weapon that would basically be for a Mage Slayer type character. I want the magic item to grant ADV to the user against all spells.

Is there a way to code this in 5E since I do not want to grant ADV for other saves?

Thanks.

[Zacchaeus]

Saving throws aren't attacks as such so there's not really a way to filter out what kind of attack is being made on the target. So you'd need to do this manually using just an ADVSAV: effect on its own or pressing the ADV button just before the spell is cast.

[LordEntrails]

What about Magic Resistance? Doesn't that NPC ability grant adv on saving throws versus spells? Not sure how that would be applied to a PC though.

[Zacchaeus]

Magic resistance would reduce the damage from a magical attack. It wouldn't grant any advantage to the attack itself. I think you may be thinking of the Gnome's magical resistance which is a specifically worded NPC trait (which can apply to a PC as well). However that only gves advantage against certain saving throws and not all of them.

[Klandare]

Magic resistance would reduce the damage from a magical attack. It wouldn't grant any advantage to the attack itself. I think you may be thinking of the Gnome's magical resistance which is a specifically worded NPC trait (which can apply to a PC as well). However that only gves advantage against certain saving throws and not all of them.

Actually it turns out that just putting an effect of:

Magic Resistance

onto a character will grant the advantage to saves just for spells.

Had to find a creature that had that an ability (Pseudodragon) and tested against it with spells from a Mage (and then also the other items Frightening Presence and Breath Weapon from a Dragon) and it only gives the ADV to saves for the spells.

Yay! Now I can create a weapon with that on it.

[Zacchaeus]

Ah, indeed. Obviously had too much Christmas spirit. I completely forgot about that, even after LE pointed it out (I was thinking RESIST:magic instead of magic resistance).

[LordEntrails]

Sounds like just about the right amount of Christmas Spirit!