"Into The Great Wilde Open"
The level of the Creature determines the Target Number, just as with combat. Thus, bribing a guard works much like punching him or affecting him with an esotery. This is true of persuading someone, intimidating someone, calming a wild beast, or anything of the kind. Interaction is an Intellect task. Being Skilled in persuasion, intimidation, bribery, deception, animal handling, or something of that nature can decrease the Difficulty of the Task, if appropriate.