A method of deception that has been used many times before and should therefore be well-known.

(programming) A form of restricted template expansion in C++, characterized by an in-class friend function definition appearing in the base class template component of the curiously recurring template pattern.

(Canada and US, ice hockey) The triple achievement of a goal, an assist for a goal, and participation in a fight, within a single game.

plural of Gordie Howe hat trick

(idiomatic) To know all there is to be known about a certain discipline.

(idiomatic) Synonym of ace up one's sleeve

plural of trick up one's sleeve

(informal)

It is impossible to change people's habits, traits, or mindset.