So I've been reading through ToA (DnD 5E) prepping my campaign, and part of it brought up a question I've never really thought too deeply into.
How do you end/destroy/anything to an anti-magic field? Yes, the PC spell is a one-hour concentration, but many campaigns have items or hallways with fields. Sometimes there's a lever or other switch to turn the field on/off, but barring that, is there any possible way to stop or eliminate the field? If my characters know there's one present (likely a trap, of course), is there any way for them to remove the field, or shut it down in any way?
RAW/RAI, from what I can find even higher-level spells have no chance, they don't make a check to succeed or anything. Prismatic Wall is the ONLY magical effect that goes through an AMF.
Best Answer
There is a way, but you won't like it
Antimagic field has one written exception to its magic cancelling effects (PHB, p. 213, bold added):
If a deity has come to the your plane and is helping your party directly, they could cast spells that affect the area in the antimagic field as though the field wasn't there. Although this wouldn't remove the field, it would mean it might as well be gone for most intents and purposes.
Note that even a deity could not cast dispel magic on the field (unless there was a specific rule in their stats indicating they could), since the statement that "Spells and magical effects such as dispel magic have no effect on the [field]" (PHB, p. 214) is not subject to the exception applied to deity level magic.
Usually, an antimagic field has a source of some kind (a beholder's central eye, a magic item, the spell of the same name), and eliminating that source should work. But in the absence of that, there is no consistent way to eliminate the field.
The question is similar to the question "is there a foolproof way to eliminate light?" The only real answer is "it depends on the source of the light." Similarly, the way to remove an antimagic field will depend on its source.