This article contributes to the current debate about why people follow the law even when they are not subject to legal sanctions, as when there are no police and little danger of a lawsuit. Most recent scholarship in this area takes the form of norms theories, suggesting that social norms rather than laws shape behavior and that deviations from the norm are punished by either social or internal sanctions. Robert Sugden, however, proposes that order may develop “spontaneously” in the many areas of life where abiding by the rules minimizes the risk of costly confrontations with others and is thus in the interest of all parties. When this is true, the threat of little or no sanctions plays no role in regulating behavior. This article tests Sugden's theory against a simple property system, that of the California gold mines, in which individual miners held small claims subject to strict work requirements. The evidence of eyewitnesses shows that the stability of the regime did not depend on norms, but on the reasonable prediction that other claim holders would themselves stand up for their rights under the local mining code. Disputes about the rules and their application were submitted to arbitrators, whose decisions were accepted by the parties and did not need to be enforced. The California experience thus provides an example of a stable property regime for which game theory has a more satisfying explanation than do any of the norms theories.