2.1. Bide

From the Basic Ability List in the Appendix:

Time: Action Target: Self

Gain one Persistent Stack of Biding:

You can use any Action as a Reaction with the Trigger:

When a creature in Shooting Distance(16u) starts an Ability.

When you perform an Action as a Reaction in this way, you lose one Stack of Biding.

When first performing this Ability, you can choose a Reaction Trigger of your own to add to the standard Biding Reaction Trigger.

Next Up: 2.1. Move