Mechanical interlocking enables materials whose components remain associated while retaining internal mobility. Such assemblies can undergo large rearrangements without losing cohesion, yet resist deformation when contacts restrict further motion. Understanding this behavior requires connecting the motions of individual components to the collective mechanics of the materials. In this talk, I will discuss polycatenated architected materials and entangled helical weaves as model systems for connecting local motion to the collective mechanics of the assembly. I will describe how these architectures form and what prevents their components from separating, then examine the sliding and rotation that remain possible within them. Reconfigurable knot chains and swellable architectures will illustrate how changes in geometry alter these motions and the resulting material response. I will close with our progress toward nanoscale interlocked assemblies, where thermal motion raises questions about the lifetime and relaxation of interlocked states and how these processes affect collective phase behavior.