Give SS a profession on a slip of paper (or get them to think of one).
Either in the Hot Seat (open class), or in pairs, SS try to guess the profession without asking more than twenty questions.
SS must ask yes/no questions e.g: Do you wear a uniform? Do you work at night? Do you use a gun? Do you wear a hat? Are you a soldier? Etc. SS only answer correctly formed questions.
A small bell may help here for re-phrasing and soul-searching.