From the Game's Introduction:
Les personnages se rencontrent dans un monde onirique, où ils vivent des aventures fantastiques, par exemple combattre les Loups qui se nourrissent des rêves enfantins.
User Translation from French:
The characters find themselves in a world of dreams, where they have fantastic adventures, for example fighting the Wolves that feed on children's dreams.
One of seven role-playing games published on one page. The theme for this one is "Dreams".
Each character is defined by three traits: one relating to a legendary individual, one to an animal, and one to an abstract concept.
Task resolution is performed by rolling a number of twenty-sided dice equal to one greater than the number of applicable traits (so always at least one die). The single highest die roll is kept, and compared to a target difficulty number or opposing roll. A roll of 5 or less (or a difference of at least 5 between opposing rolls) causes the temporary loss of one trait until waking up. A roll of 1 (or a difference of at least 10 between opposing rolls) causes the character to immediately wake up (difficulty 15 to find one's companions upon falling asleep again).