Assessment relativism (henceforth AR) is a type of truth relativism1 that has been developed by John MacFarlane in a series of works,2 culminated in his 2014 book Assessment Sensitivity: Rela- tive Truth and Its Applications. Relativism about truth is the thesis that (some) truths are true merely relatively.This view is mainly motivated by the attempt of making sense of the possibility of disputes where none of the competing opinions seems less legitimate, or less true, than the others.This phenomenon is known under the label “faultless disagreement” and, roughly put, it concerns situations where one party accepts while the other rejects that things are so-and-so but neither of them is, not even in principle, off-track and guilty of any mistake.3 To get a proper grip on AR and to distinguish it from other versions of truth relativism, three questions are particularly relevant: (i) which truths are relative and which aren’t? – Sec- tion 2; (ii) what is truth relativism and what are the bearers of (relative) truth? – Section 3; (iii) in what sense is truth relative according to AR? – Sections 4–6. Section 7 discusses two challenges to AR.