You mean the 3.5 edition where the persuasion skill (
diplomacy) explicitly only influenced NPCs?
Diplomacy (Cha)
Check
You can change the attitudes of
others (nonplayer characters) with a successful Diplomacy check; see the Influencing NPC Attitudes sidebar, below, for basic DCs. In negotiations, participants roll opposed Diplomacy checks, and the winner gains the advantage. Opposed checks also resolve situations when two advocates or diplomats plead opposite cases in a hearing before a third party.
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Influencing NPC Attitudes
Use the table below to determine the effectiveness of Diplomacy checks (or Charisma checks) made to
influence the attitude of a nonplayer character, or wild empathy checks made to influence the attitude of an
animal or
magical beast.