Outer space is crucial to the functioning of the modern state – any state – and is indispensable to the great powers as an economic and military force multiplier. Developments of recent years have accelerated the battle to fill in ‘gaps’ in the existing legal regime governing space access and use. With commercial and military stakes so high, this presents a real-time case study in the formation of international law (IL) against the backdrop of classic international relations (IR) power struggles, uniting ‘real world’ and academic debates. Using a constructivist–rationalist approach, I explore how states strategically deploy international law to advance political interests in outer space. The legal realm as a medium in which politics plays out gives states a set of unique and powerful tools for advancing their own interests, and for altering the strategic operating environment of others. States thus instrumentalise law for strategic advantage, or engage in ‘strategic use of law’. I break down this broader method into four distinct, but complementary, sub-tactics that speak to the different ways states engage with law to achieve their broader interests: ‘legal contest’, ‘legal window-dressing’, ‘extra-legal pressure’, and ‘compliance-leverage disparity lawfare’. Applying this typology to a range of case studies, I analyse ongoing legal battles around arms control in outer space, space resource utilisation, mega-constellations, and the ‘race’ for the Moon and cislunar space. By comparing these examples, I tease out multiple ways by which states seek to leverage IL as a source of power in ensuring access (or denying others access) to space and its concomitant commercial and military advantages. While outer space provides a fruitful, and currently very topical, domain in which to apply this typology, the typology is a standalone contribution that could likewise be applied in other empirical domains.