At Play, Vol. 3 is a compilation album from the Canadian progressive house musician deadmau5 and the third of the At Play series. Like the previous At Play albums, this album consists of "10 Full Length DJ Friendly Tracks" as it says on the sleeve. Half of the tracks are from his 2006 album Vexillology and the last two are singles from 2007. The tracks "Cyclic Redundancy" and "Templar" were previously released on the 2007 EPFull Circle. However, deadmau5 himself claims to have had "nothing to do" with the album's release.