What are the criteria for patentability in your jurisdiction?

An invention must be novel, useful and unobvious. The subject matter must be ‘statutory’ to be patent eligible as well. 

What are the limits on patentability?

In order to be considered statutory subject matter in Canada, the subject matter must be an art, process, machine, manufacture or composition of matter. Thus, some subject matter is not patent eligible. No scientific principles or abstract theorems may be patented, such as mathematical formulas, discoveries of laws of nature or purely mental operations. Other excluded subject matter in Canada includes methods of medical treatment or surgery and higher life forms.

Are there restrictions on any other kinds of invention?

Higher life forms, methods of medical treatment, inventions requiring the exercise of professional skill, matters of aesthetics or fine art and disembodied mental processes lacking a method of practical application are not patentable.