Some artistic practices of the XXth century seem to make a choice for creativity: develop a work from a set of rules and set it as a play area where the artist has to associate and combine a number of elements. The first constitutive moment of the work is thus a "consultation", a reflection on the requirements that may be used and adopted. Our hypothesis is as follows: creating with rules and considering a work as a game is a way for the artist to explore a system of possibilities. Having to use, in music, a particular set of sounds requires the composer to conceive new compositions modes and to ignore the rules of classical harmony, as shown in Arnold Schoenberg's work. Placing themselves, in literature, under the aegis of prescriptions the himself have developed allows writers to establish what Michel Leiris called a "say different". Composition and writing have the same goal: to ask, like the painter Gérard Gasiorowski, "what to do?" with the artistic material.
