The actions you can perform with a given skill are sorted into those you can use untrained and those that require you to be trained in the skill, as shown under each skill. The untrained and trained actions of each skill appear in separate sections within the skill's description.

Anyone can use a skill's untrained actions, but you can use trained actions only if you have a proficiency rank of trained or better in that skill. A circumstance, condition, or effect might bar you from a skill action regardless of your proficiency rank, and sometimes using a skill in a specific situation might require you to have a higher proficiency rank than what is listed on the table. For instance, even though a barbarian untrained in Arcana could identify a construct with a lucky roll using Arcana to Recall Knowledge, the GM might decide that Recalling Knowledge to determine the spells used to create such a construct is beyond the scope of the barbarian's anecdotal knowledge. The GM decides whether a task requires a particular proficiency rank.