[1] Although some sources make it out to be simply a particularly deadly spear, others—notably the Book of Leinster—state that it could only be used under very specialized, ritual conditions: The Gáe Bulg had to be made ready for use on a stream and cast from the fork of the toes.
In the Táin Bó Cuailnge, Cúchulainn received the spear after training with the great warrior mistress Scáthach in Alba.
Cúchulainn's use of the Gáe Bulg in the Táin Bó Cuailnge exemplifies its deadliness and the gruesome condition in which it leaves its victims.
As it is stated in Ciaran Carson's translation of The Táin: Láeg came forward and cut Fer Diad open and took out the Gáe Bolga.
[4] Several notable Celtic scholars, including Joseph Loth and Kuno Meyer, have preferred to derive it rather from Old Irish bolc "gap, breach, notch" (cognate with Welsh bwlch), suggesting a linguistic link with the second element in the name of Fergus mac Róich's sword, Caladbolg and King Arthur's sword Caledfwlch.