Enrichment provision is legally required for pigs in the EU under Directive 2008/120/EC, yet implementation varies enormously in effectiveness. Pigs have a powerful rooting drive - exploring substrate with the snout for extended periods daily - that cannot be fully satisfied by hanging chains or rubber objects. Research distinguishes effective from ineffective enrichment using occupancy measures and preference tests. High-quality enrichment includes destructible/manipulable materials: straw, woodchip, peat, compost, and mushroom substrate. Straw scoring highest in occupancy studies, engaging pigs for 25-40% of active time. Fixed objects (chains, balls, rubber) are used briefly and habituate rapidly. Provision of rooting substrate simultaneously addresses tail-biting risk, reducing need for tail docking. EU enforcement of enrichment requirements has historically been weak; the 2022-2027 Animal Welfare Strategy aims to strengthen standards. Research demonstrates that multi-modal enrichment providing novelty, destructibility, and occupational complexity delivers superior welfare outcomes.