Motor fluency influences preference judgments: people tend to like things they can manipulate easily. Yet, links between motor fluency and preference extend beyond the domain of concrete objects that afford physical manipulation. People implicitly associate abstract ideas like goodness and intelligence with locations in space that ordinarily afford fluent actions. How do these abstract associations develop? Here we tested whether children’s preference judgments are influenced by implicit affordances of imaginary objects. Children imagined helping a cartoon character store toys in a bookcase, drawn next to the character. They tended to assign toys the characters liked to locations on the shelves that would afford fluent actions and toys they didn’t like to locations that would afford less fluent actions. Crucially, the ‘fluent’ location was determined by implicit constraints on the character’s actions, not by the child’s own action affordances. Imaginary affordances may help link concrete motor actions with abstract preference judgments.