Legal systems must decide how to protect legal rights, using property rules or liability rules. Property rules work best when parties can negotiate easily, while liability rules are better when negotiation is hard. Recent studies suggest liability rules may be better even with low negotiation costs, but new research shows property rules are more effective in these situations. Behavioral studies reveal that under property rules, parties share gains fairly and are more likely to reach agreements. In contrast, liability rules lead to selfish behavior, making negotiations difficult and often unsuccessful. This can result in the need for coercion, which harms efficiency and personal freedom.