Do bunk beds have to be fixed to a wall?

This depends on the location, everyones room is different. The bunk bed is free standing, however bunk beds are top heavy so can move due to an uneven floor or being pulled forward when climbing a ladder. This is not a design fault but the nature of a top heavy bed, especially a high sleeper or loft bunkbed. On such occasions we supply brackets, you can attach to the wall or to the skirting board. This simply holds the bed in place. This condition is not specific to Strictly Beds and Bunks but applied to all bunk beds.