It is commonly thought that moral rules and principles, such as 'Keep your promises,' 'Respect autonomy,' and 'Distribute goods according to need (merit, etc.),' should play an essential role in our moral deliberation. Particularists have challenged this view by arguing that principled guidance leads us to engage in worse decision making because principled guidance is too rigid and it leads individuals to neglect or distort relevant details. However, when we examine empirical literature on the use of rules and principles in other domains, we find that people can learn to use rules discriminately and that rule-based models tend to outperform even expert judgment. I argue that this evidence poses a problem for the moral particularist. If the particularist claims that we should not rely on decision-making rules when making practical decisions and it turns out that these rules help us make better decisions, then the particularists' prescriptive account is deficient. However, if the particularist claims that we should rely on practical decision-making rules but not on moral rules, she needs to explain how practical rules are different from moral rules and why we should rely on the former but not the latter. [ABSTRACT FROM AUTHOR]