Students' engagement with fictions in the form of "word problems" plays an important role in classroom practice as well as in theories of mathematical learning. Drawing on the Dutch historian Johan Huizinga and the Austrian philosopher Robert Pfaller, I show that this activity can be seen as a form of "play" or "game," where it is pretended that mathematics is useful in real life in a way that it is not. With Pfaller, I argue that play can take hold of the imagination of the players, infusing everyday life with meaning borrowed from the imagery of the play and that these effects are more powerful when the play is forced and takes an institutionalized form. I show that mathematics education does in fact have these characteristics, including sophisticated mechanisms for translating in-game performance (test scores) to real-life goods (grades and examinations). A central theme of the article is the perceived discrepancy between mathematics education as it is, and how it supposedly could and should be in light of the properties of mathematics. The analysis implies that this gap actually is an effect of play and thus an inherent property of mathematics education itself.