Budget rules are both necessary and arbitrary, apply one-time or over time, and are frequently associated with some numerical target. The Budget Enforcement Act (BEA) rules of 1990 worked primarily because they enforced an agreement already made, backing up a broad political consensus with much of the explicit deficit cutting legislated up front. Conditions today are very different. No political consensus now exists, yet the task is even harder: some control over existing entitlement growth is required, e.g., through automatic adjustments. Various other issues, such as sunsets, rule suspensions, and technical feasibility are also examined.