Evidence of collaborative composition of poetry goes back to the earliest documented phases in the history of Arabic literature. Already during pre-Islamic times, poets like Imruʾ al-Qays used to challenge others to complete their impromptu verse and create poetry collaboratively with them. This practice—commonly called iǧāza or tamlīṭ and essentially different from the better known poetic dueling of the naqāʾiḍ (flytings)—has shown remarkable stability and adherence to its form and dynamics in the pre-modern Arabophone world. In this article, I will discuss evidence of collaborative poetry from pre-Islamic times to the early seventh/thirteenth century, in order to present a picture of the typical situations in which it was practiced, its functions, its composition process, and formal aspects. Although usually not producing poetic masterpieces, this practice has the merit of revealing much about the processes of composing classical Arabic poetry in general. In this respect, its study and critical assessment are highly important, given the fact that medieval Arabic literary criticism does not always reflect praxis or focus on the actual practicalities of composing poetry. This practice and the contextualized way in which it was preserved allow us to see vividly the inextricable link between poetic form and the conditions in which poetry was created. It likewise sheds light on the intricate ways in which poets resisted, influenced, and manipulated others by poetic means. Based on the obvious fact that collaborative composition is imbued with the spirit of play, I offer at the end of the article criticism of Johan Huizinga’s famous play concept and his (much less famous) views of early Arabic culture and poetry in light of the evidence I studied.