User blog comment:The Milkman/Shades of Purple/@comment-2250460-20120929231424/@comment-24174486-20120930012355

With ME1, you didn't need full Paragon or Renegade meters in order to get the maximum Charm/Intimidate scores. I believe you only needed about 75% of each meter in order to unlock all 12 ranks of the talents. Your military history gives a boost to your Paragon/Renegade meters and your pre-military history gives a bonus to how fast you gain Paragon and/or Renegade points.

ME2 calculates Charm and Intimidate by comparing the number of Paragon/Renegade points you've obtained with the maximum number of Paragon/Renegade points you could have obtained by that point (respectively), meaning that the meters actually tell you very little. Because many Paragon and Renegade points are mutually exclusive, this makes it normally impossible to have both 100% Charm and 100% Intimidate. If you imported an ME1 save and/or invest in the passive class "powers", then you can potentially have greater than 100% of the possible Paragon/Renegade points, making Charm/Intimidate checks a breeze. This ends up making it nigh-impossible for non-import players to play an effective Paragade/Renegon because they don't get the morality bonus from ME1.

In conclusion: ME2's persuasion system is incredibly stupid.