Hogwarts he is detected using magic in the presence of Muggles, a serious offence among the wizarding community. Dumbledore argued in Harry's defence, stating that it was done in self-defence, and that the Ministry has no authority to expel students – such powers are invested in the Headmaster and the Board of Governors. Snape has attempted to have Harry expelled, and he attempted to have Harry's father, James Potter, expelled when they were at Hogwarts together. The only student known to have been expelled is Hagrid, for the murder of Myrtle with an acromantula believed to be the Monster of Slytherin
Hogwarts tend to "move around", and so do the stairs in the grand staircase. Witches and wizards cannot Apparate or Disapparate in Hogwarts grounds, except when the Headmaster lifts the enchantment, whether only in certain areas or for the entire campus, so as to make the school less vulnerable when it serves the headmaster to allow Apparition. Electricity and electronic devices are not found at Hogwarts. In "Harry Potter and the Goblet of Fire", Hermione indicates that due to the high levels of magic, "substitutes for magic (that) Muggles use" such as computers, radar and electricity "go haywire" around Hogwarts. Radios