Upgrading Properties
Properties can be Upgraded through the use of certain Masteries, Items or Abilities.
When Upgrading a Property, advance along the progression list from your starting Property. Moving once per Upgrade.
Example: Olivine the Oricalcai is performing a Study Check under the effects of the Advantage Property due to his Mastery of Thought Ability. His ally Jimmy the Second performs the Help Action to give Olivine another instance of Advantage. Due to Mastery of Thought Olivine's Advantage is Upgraded to Reliable. This means Olivine's Study Check is now under the effects of both the Reliable and Advantage Properties.
The same would be true in the case of Disadvantage being Upgraded to Unreliable.