Key Attribute: Charisma.

The Diplomacy skill represents a character's ability to negotiate, persuade, and interact effectively in social situations. It governs efforts to change the attitudes and behaviors of others through flattery, negotiation, or intimidation. Diplomacy can be used to settle disputes, secure favorable agreements, gather information through conversation, or defuse tense situations before they escalate into violence.

You will roll your Diplomacy when attempting to Calm a Foe, Gather Information, Make a Request or Make an Impression.