Quote Originally Posted by johnbragg View Post
It's more the "1 hour/caster level."

Even with the Giant's diplomacy rules a +10 magic bonus gives that 2nd level bard from his article a decent chance to solo a dungeon and walk out with the MacGuffin. His Bard had a +14 to Diplomacy, cast a 1st level spell and that goes to +24.

So he strolls past the guardmooks (low HD, low Wisdom so DC 15, +5 Enemy, +5 Unfavorable deal puts it at DC 25--guaranteed success), and similarly past the minibosses.

Against an 8th level BBEG with a +2 to Wisdom, start at DC 25, +5 Enemy, +5 Unfavorable deal (you give me the MacGuffin and you get to escape unharmed because as a 2nd level bard alone I'm a terrifying threat and by the way give your former minions all your cool stuff I promised they could have to get them to switch sides), DC 35. Roll an 11 or better, the BBEG hands you the MacGuffin. 10 or less, the DM pulls out his hair as he has to run both sides of the BBEG vs The REst of the Dungeon fight while the Bard Inspires Courage.

It's 1 hour per caster level duration.
To be clear, my suggested Charm Person still only works on one targeted NPC.