Under the current system for diplomacy, a second-level character with good charisma and the right skill selection can move virtually any hostile creature with whom he or she shares a language to indifferent, half the time, without even needing feats like skill focus (diplomacy) or persuasive. By level eleven, this character can do it at any time. This, clearly, cannot be allowed.

Therefore Ba is going to use Rich Burlew's system of diplomacy, found here. This is not to penalize characters with ranks in diplomacy, but simply to provide a more sensible system for the use of that skill.