Most are varied by the company, in relation to recent incidents, where it is felt by the training department, where additional training is possibly desired.
As I AM the training department at our small ad-hoc charter airline, I do the same, however....I personally completely brief the scenario prior to the sim detail.
Why?
In this way, I feel that the crews under check experience true-to-life situations, with the airplane.
IE: not some nefarious circumstance situation that was dreamed-up by a 'malcontent'.....in some other airline.
PS.
Far too many malcontents in training, today.
