Two particular features of hyper-legislation are the broad discretion that laws confer on government officials, and the extent to which they authorise officials to make decisions that restrict fundamental rights. These issues pose a challenge for courts, whose role it is to ensure that discretionary powers are exercised lawfully while respecting the mandate of democratically elected governments to assess risks to national security and to determine government policy accordingly. We assess judicial practices in reviewing decisions ostensibly taken for national security. Our research reveals that judges rely on a variegated approach to deference that affords different degrees of scrutiny to (1) the existence of a security threat and (2) the appropriateness of government action taken in that context. We then analyse the normative and practical considerations influencing adjudicatory practice in this area and assess this approach in terms of the separation of powers and rights protection.