join a duelling club (the first one is in the great hall, the others are unlockable through the game) sign up for a duel on the notice board and duel!
When you duel and only when you duel will it be co-op
duel against each other
Go to the Paved Courtyard
Harry Potter and the Half-Blood Prince is described as a third-person action shooter. Basically, you actually see Harry as you move him and you duel and interact with the environment using spells.
Mix potions,duel your frinds, start a new file.
The spell that Harry Potter used to cause Draco Malfoy to bleed continuously in the bathroom duel scene of "Harry Potter and the Half-Blood Prince" is called "sectumsempra".
Not in the game proper. There is a feature where you can duel against your friends, playing as various characters including Malfoy.
The person that has a duel with Harry James Potter in The Chamber of Secrets is Draco Malfoy
In the book, yes - Morfin Gaunt has a snake. In the film not really; Tom Riddle tells Dumbledore that he can talk to snakes.
Draco Malfoy challenged Harry Potter to a wizards duel at midnight. The chapter in which this duel was due to happen is called The Midnight Duel. Draco was actually tricking Harry and tipped Argus Filch off so that Harry would be caught out of bed.
Pottermore allows you to duel with other members.
Besides the cave scene from the Half Blood Prince, a good scene to analyze for AS Film studies is when Dumbledore and Voldemort duel in the Ministry of Magic's entrance in Harry Potter and the Order of the Phoenix.