Even though games have been studied and described from multiple perspectives, highlighting their importance in human development, their use in education seems to be largely restricted to preschool education. In this sense, teacher motivation for the integration of new methodologies (including games) seems to be relevant when studying change and improvement in education. The aim of this paper is to present a scale that can help to study motivation for the use of the game. We report its psychometric characteristics. The Motivation Scale for the Game (EMJ, by its acronym in Spanish) has been built from Eccles and Wigfield’s Expectancy & Value Model (2002). The EMJ scale asses perception of competence to implement playful activities/elements in instructional design (expectation) and the value assigned to the 4 components of task value (utility, importance, interest and cost). The structure of the instrument, its theoretical foundations and its factorial structure and reliability are reported from a Chilean teachers simple. The results shows psychometric characteristics that make EMJ a solid, reliable and valid instrument that can provide clues for motivational intervention in the school setting