How to animate a chain unwrapping and sliding along a chest Please forgive me in advance if this is too basic a question. (I'm a beginner to Blender and animation). 

From a high level perspective, what's the best way to animate a chain unwrapping and sliding out from around/under a treasure chest. Think of the chain wrapping the chest several loops, fastened by a padlock. The padlock is unlocked, and then the chain unwraps itself WHILE sliding out from under the chest (so there's some rotation and translation of individual links at the same time there is translation along the faces of the chest for the entire chain). 

I know a bit about armatures and key shapes, having done some basic tutorials.

Many thanks in advance for some advice as to how I should think about setting up the animation!
I would create a curve; animate it along the wanted path, using hooks or the "AnimAll" addon; model two elements of the chain and repeat them with an array modifier; add a curve modifier to the mesh, pointing to the animated curve, then move along the X axis the mesh to have it follow the animated path.