The Bo-staff first appears in the Big Bad World mini-series, when Robin has a run in with Lady Shiva. After training him, (a crash course in all things deadly) Lady Shiva asks the boy to pick any weapon to continue. While there are no blades on the staff, it mirrors Robin's personality as well as his mentor's and predecessor's as a non-lethal tool of maiming. Robin puts in his own little signature into his first wood stick by slightly slicing one edge to give it the sound of a bird whistle when moving.
He also uses this stick against Jubilee in Marvel vs DC/DC vs Marvel.
While the Bo-staff gives Robin more reach, he can also retract the stick, making for a more portable staff.