10 Things We Learned From Universal Orlando's A Celebration Of Harry Potter Q&As

6. Jason Isaacs Broke Daniel Radcliffe's Phone

The cast talked about all the pranks on set, the most popular one being changing the language on a person's unsuspecting mobile phone.

Isaacs recalled the time when he changed Daniel Radcliffe's phone into Korean. Unbeknownst to him that despite memorising the route to turn it back to English, the Korean set up for a Sony phone was different to the English version. In the end they had to call Sony to fix his phone, which kind of took the fun out of the prank.

Matthew Lewis also said that Rupert Grint hit him with a dart. As Ron Weasley himself was very good with a dart, Lewis speculated that it might have been on purpose.