Negotiating power generally comes from one of three sources, according to Northwestern University professor Adam D. Galinsky and New York University professor Joe C. Magee:

1. A strong BATNA. Your best alternative to a negotiated agreement, or BATNA, is often your best source of bargaining power. By cultivating a strong outside alternative, you gain the power you need to walk away from an unappealing deal. For example, a home buyer could improve her power in a negotiation with a seller by finding another house she likes just as much.

2. Role power. Power can come from a strong role, title, or position, such as a high rank in an organization. When negotiating with your boss, for instance, you sometimes may need to cede to his preferences because of his high status.

3. Psychological power. Negotiators can bring a sense of psychological power to the table—the feeling that they’re powerful, whether or not that’s objectively the case. Simply thinking about a time in your life when you had power can bolster your confidence and improve your outcomes, Galinsky and Magee have found.

Regardless of its source—a strong BATNA, a powerful role, or a feeling of power—power is critical to improving your negotiated outcomes. When preparing for a negotiation with a powerful counterpart, try to increase your own sense of power on as many of these levels as possible.