A cam system for an archery bow including a module that is readily attached to and detached from a cam while leaving the cam on the bow. The module can include a draw stop selectively moveable relative to the module, even while the module is joined with the cam, to adjust the draw stop to specific locations corresponding to different draw lengths and/or draw stop walls of the bow. The module can include a recess that surrounds only part of an axle joining the cam and bow so the entire module is removable from the cam without removing the axle. The cam system can include indexing features that precisely and consistently align features of the cam and module. These features can include first and second indexing posts, and corresponding indexing holes, that register with one another to precisely align the cam and module when joined.