All Cahills must take a Cahill Oath, pledging allegiance to the Cahills and to the Cahill Council of Three, as well as to Gideon and Olivia Cahill, patriarch and matriarch of the Cahills.

The Cahill Oath:

I, (name), swear to bring peace and goodwill to the world. I will not betray fellow Cahills and will be opposed to the Vespers. I promise to be faithful to the Cahill Cause and its supporters. I will obey the Cahill Council of Three. So take me as one of your own.

The Cahill Oath was devised by Cahill Two in the early stages of the army and approved by Cahill One.