stack the deck in (someone's or something's) favor

To create, contribute to, or manipulate a situation in a way that results in an unfair advantage over someone or something else. (Likened to a bookmaker rigging the odds of a betting to ensure that they win and others lose.) With our two-day seminar, we'll teach you how to stack the deck in your favor in any business negotiation. These big corporations stack the deck in their own favor by having access to huge, high-level legal firms that can out-litigate any small time business that may stand in their way.