When an adventurer performs this action, they spend the required amount of tenacity to trigger a class ability. You may gain 1 light fatigue to change battle form before resolving the ability. You can only trigger each non-enduring class ability once during each turn at its correct timing specified in its ability text.

Note that some class abilities are not actions. These class abilities have either the enduring keyword and are ongoing or have the interrupt keyword and must be triggered at the time specified in the ability’s text.