 An extension of a rights-based moral theory to indeterministic cases can be obtained by prescribing that if A has a right that B does not bring about a certain outcome, then A also has a right that B does not perform any action that (at all) increases the probability of that outcome. Unfortunately, such a strict extension of rights is untenable in social practice. Presumably, A has the right not to be killed by B, but it would not be reasonable to extend this right to all actions by B that give rise to a very small increase in the risk that A dies — such as driving a car in the town where A lives. Such a strict interpretation would make human society impossible. 