Desde que esta pergunta foi feita, Jeremy Crawford mudou de idéia sobre como isso funciona.
Na coluna Respostas às Regras de Abril para o Conselho de Sage , Crawford tem isto a dizer :
Does moonbeam [or Spirit Guardians] deal damage when you cast it? What about when its effect moves onto a creature? The answer to both questions is no.
Ele continua a elaborar:
Reading the description of any of those spells, you might wonder whether a creature is considered to be entering the spell’s area of effect if the area is created on the creature’s space. And if the area of effect can be moved—as the beam of moonbeam can—does moving it into a creature’s space count as the creature entering the area? Our design intent for such spells is this: a creature enters the area of effect when the creature passes into it. Creating the area of effect on the creature or moving it onto the creature doesn’t count. If the creature is still in the area at the start of its turn, it is subjected to the area’s effect.
Esta é a lista de mágicas ao qual o artigo se aplica:
- barreira da lâmina
- cloudkill
- nuvem de punhais
- tentáculos negros de Evard
- proibido
- raio de luar
- tempestade de granizo
- guardiões espirituais
Compare com seu tweet original e follow-up . Veja a resposta da DuckTapeAl para mais detalhes.