It is very difficult to accidentally summon a demon. Unless you're the Doctor.

During an exploration of an abandoned mansion, the Doctor came across a faded circle made of chalk on the floor and a book opened to a certain page. And, of course, who wouldn't read aloud the verse the book was open to? That's where you come in.

After he recites the verse written in the book, you appear before him in a flash of fire and smoke. The Doctor steps away defensively.