If you have kept up with the legal news in your field, the main topics for ‘debate’ won’t come as a surprise.
Often, these are the same ones per types of chambers. In the 2017 round, Brexit and the impact of the Trump administration was a hot topic at many different types of chambers. Anonymity for defendants in rape cases came up at almost every criminal chambers. You will usually be asked whether you are for/against a proposition, or asked which side of the proposition you prefer and to justify your position. You are then likely to be asked to present the opposing view.
The best way to prepare for debate questions is to keep up with the legal news
A candidate on the student room forum suggested taking each debate topic and writing up points for/against. This method has been tried but frankly it is a waste of time. Moreover, you are expected to be able to think on your feet and articulate your points persuasively – you will be best equipped to do this the more you read and think, rather than preparing detailed answers in advance.
When answering debate questions (or during an advocacy exercise), you must remember to speak slowly and clearly. Make three points, no more. You also, when challenged, need to listen properly and respond to exactly what you are being asked. Don’t panic if a point you make is vehemently disagreed with and/or challenged by several panel members – this is normal.