Confundus Charm
The Confundus Charm is a bewitchment that muddles its target's judgement, and a strong enough one can fool even a powerful magical object into forgetting its own rules.
Snape tells the Minister that Black must have put Harry, Ron and Hermione under a Confundus Charm, judging by their belief that Black might be innocent. Moody argues that only an exceptionally strong one could have fooled the goblet into overlooking the rule that the tournament admits just three schools. Snape suspects that Dawlish has been Confunded, a thing he calls nothing new for that Auror, though Yaxley insists Dawlish seemed entirely sure of himself.
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