The members of the Chinese writers' guilds were those who not only provided scripts for plays, but participated in the creation of a great many kinds of entertainment. The first members of the writers' guilds were actor-playwrights, but with the invasion of the Mongols and the disruption of the Imperial examination system, some men of letters became members of the writers' guilds. The combination of artistic talents of the actor-playwrights and the scholar-playwrights directly affected the literary merit of Yuan drama. Moreover, as an entertainment art based in competitive economics, the writers' guilds were of primary importance to the drama of the Yuan period.