Although ideal L2 self has been considered an importance source of L2 motivation, little empirical research has examined its specific properties and their motivational capacities. This study investigates how five properties of the ideal L2 self--centrality, accessibility, plausibility, vividness, and the existence of plans and strategies--predict two motivational criteria: the ideal L2 self's self-guiding role and general intended learning effort. It also proposes and tests an elaborateness scale for learners' descriptions of their ideal L2 selves in order to examine how descriptive elaborateness relates to the properties of the ideal L2 self and to motivation. Forty-four students wrote narratives about their ideal L2 self, and completed a questionnaire on specific aspects of the ideal L2 self and their motivation in general. The analysis finds only centrality to be a significant predictor for intention to learn, and only accessibility and plausibility to be significant predictors for the ideal L2 self's self-guiding role. The elaborateness of narratives was weakly related to a global ideal L2 self, as well as to the centrality and plausibility of the ideal L2 self. Elaborateness was also related to future intended learning effort, but not to the ideal L2 self's guiding role.