This tag is a subset of physics, and applies to the physical properties of ropes and other ropelike objects. It does not correspond to a specific branch, although a lot of the problems may seem similar to parts of fluid dynamics.
Rope physics is significant as they present unique challenges to game development due to how different it can be handled compared to other objects. It doesn't have a rigid body shape like most game objects, it instead has a malleable shape that can wrap around other objects. More complexity can be introduced by adding tension and stress on a suspended rope bridge, or by simulating the gradual velocity of different segments of a swaying vine.
Games use rope physics both for its artistic flavor and as crucial parts of the gameplay. It is most often seen in varying forms of swinging around, be it from dangling chandeliers to grappling hooks. Use this tag when your question involves the properties of ropes in a game that adhere to these kinds of principles, moreso than simple "line connecting entity A to entity B".