Those whom you catch breaking a deal are more subject to your powers.
You gain a +5 bonus on Sense Motive checks to determine whether a creature is lying when you ask if it has followed the terms of a contract or deal to which it formally agreed. This includes all written and signed contracts, but also such things as witnessed oaths of loyalty and guild charters.
If you succeed at such a Sense Motive check and learn that a creature has violated any part of such a formal bargain, that creature takes a –2 penalty on saving throws against your spells, spell-like abilities, and supernatural abilities.
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SECTION 15