Fear is a special form of Disadvantage to applies to all Checks made against the source of that Fear. This discourages the Fearful creature from attacking or approaching an individual who inflicts Fear.
E.g. Fear 2 is identical to Disadvantage 2, except that it can be ignored when making Checks against any target which is not the source of Fear.
In addition, an individual suffering from Fear cannot approach the target of their fear unless they make a successful Check (UC Presence, DT 15 + Fear).
Using the same Action multiple times usually doesn’t increase the Fear status; however, the use of different frightening effects is almost always cumulative as the target becomes increasingly afraid.