Judging by the spell in the first chapter I think it's actually D&D 3.5, not 5E
That spell was the 3.5 version of cloudkill, 5E's version lacks the automatic killing of low hit dice creatures and just deals damage
If this IS 3.5 it means that
I don't think this is meant to be a comedy but the trio of aggressively British noblemen delinquents attempting to force a girl to drink tea with them made me laugh