When you hear lots of different stories about the viva it’s natural to group them together.
Short vivas. Long vivas.
Tough vivas. Easy vivas.
A presentation to start or an opening question to get things going.
Lots of questions. Hardly any.
Lots of corrections. No corrections.
Two examiners, a chair, a supervisor, a third examiner.
Expected questions and unexpected remarks.
Previously found typos and unknown errors.
And there’s more. There’s a huge range of viva experiences. Some are much more common than others. Many aspects of what “variety” your viva will be won’t be clear until you have yours.
You can’t prepare for everything, but you can be prepared. You can know the goals and expectations of your examiners, you can know what you need to demonstrate in your viva and then rise to meet that.
Long or short, easy or tough, whoever is in attendance, you can succeed.