Xanathars Guide to Everything (s. 86) behandlar detta problem:
If you cast a spell on someone or something that can’t be affected by the spell, nothing happens to that target, but if you used a spell slot to cast the spell, the slot is still expended. If the spell normally has no effect on a target that succeeds on a saving throw, the invalid target appears to have succeeded on its saving throw, even though it didn’t attempt one (giving no hint that the creature is in fact an invalid target). Otherwise, you perceive that the spell did nothing to the target.
Således slösar du stavningsplatsen som används för att motspelare. Faktum är att spellcaster trodde att det inte hade hänt någonting som hade lyckats motverka en stavning ...