The standard model (SM) of particle physics represents one of the most successful achievements of modern physics providing an accurate description of elementary particles and their interactions. However, it does leave some phenomena unexplained, as the existence of Dark Matter (DM) in the Universe. After the discovery of the Higgs boson, the last missing piece of the SM, one of the primary goals of the Large Hadron Collider (LHC) at CERN is to search for DM. DM production in proton-proton collisions can be probed by looking for missing energy signatures. In this seminar I will present an overview of the DM searches at LHC with particular attention to the techniques adopted to reduce background contamination and determine its expectation from data. I will also introduce the usage of effective operators and more complete models to interpret the results from DM searches and comment on the interplay between collider-basest searches and direct DM detection experiments.
