Search for BSM physics using challenging signatures with the ATLAS detector

Many theories beyond the Standard Model (BSM) predict unique signatures which are difficult to reconstruct and for which estimating the background rates is also a challenge. Signatures of new long-lived particles, particles with fractional or multiple value of the charge of the electron or high mass stable charged particles are examples of experimentally demanding signatures. The talk will focus on the most recent results using 13 TeV pp collision data collected by the ATLAS detector.