A Guide to Hunting Long-Lived Particles at the LHC

This article is a pedagogical review of searches for long-lived particles at the LHC. It is primarily aimed at experimentalists and theorists seeking to initiate and/or deepen their research in this field. We cover the general theoretical motivation and some example models, the main experimental techniques employed in searches for long-lived particles, and some of the important subtleties involved in estimating signal efficiencies and background rates.