Tac Ops are secondary objectives that you can attempt to achieve in certain battles to earn victory points. They are selectable, allowing you to have a degree of control over what objectives you will attempt to achieve. They are also categorised by archetype (e.g.
Seek and Destroy). Your
mission sequence will specify what category you can use and how to select your Tac Ops from that category.
Each Tac Op is kept secret until it is revealed, and it will specify when it should be revealed. Each has two conditions, marked with bullet points, that you can attempt to complete. You can score VPs from each condition once, and you cannot score VPs from a condition before that Tac Op is revealed. If a Tac Op instructs you to secretly select something, make a note of it on your roster so that your selection is recorded.