Any time a character or creature wants to activate an Extraordinary Ability, they must pass an activation roll. The character rolls their Shaping + Aptitude vs the TN listed for the ability. If they pass, it works! If they fail, nothing happens and they waste their action.
Characters may spend extra time preparing to activate an Extraordinary Ability to increase their chances of success. Each additional amount of activation time adds +10 to the TN. For example, spending an extra 2 rounds to activate an Extraordinary Ability will increase the TN by +20. Note that abilities with the Ritual Downside will take a lot longer than this.
Alternatively, a character can elect to spend a point of Shaper Energy to automatically pass their activation roll.
Once activated, the character may still need to make a separate roll to hit or otherwise affect another character as appropriate. This will follow the usual Attribute + Aptitude format and will be listed in the Description for the Ability.
Duration
By default Extraordinary Abilities have an instant duration. That means they are only active during the round of activation. A good example of this is again the classic fireball.
Duration can be increased by using the Duration or Maintained Effects.