The Right to be Treated Equal Before and Under the Law
15 (1) Every individual is equal before and under the law and has the right to the equal protection and equal benefit of the law without discrimination and, in particular, without discrimination based on race, national or ethnic origin, colour, religion, sex, age or mental or physical disability.
(2) Subsection (1) does not preclude any law, program or activity that has as its object the amelioration of conditions of disadvantaged individuals or groups including those that are disadvantaged because of race, national or ethnic origin, colour, religion, sex, age or mental or physical disability.
Equality, dignity, freedom and personal autonomy are the underlying values of section 15 (Quebec (Attorney General) v A, 2013 SCC 5 at paras 135, 140). This section of the Charter protects your equality rights. It recognizes four different types of equality (Law Society British Columbia v Andrews,  1 SCR 143 at para 33):
Equality before the law refers to equality in the administration of justice. It means that everyone should obey the same laws as everyone else.
Equality under the law refers to equality in the substance of the law. It means that laws are written so that everyone is subject to the same result.
Equal protection of the law means that everyone’s dignity and autonomy is equally protected by the law.
Equal benefit of the law means that any benefit given by a law will be enjoyed by everyone across society.
Freedom from Discrimination
Section 15 also recognizes the right to be free from discrimination. Discrimination occurs when an individual or a group suffers a distinction, whether intentional or not, based on a personal, unchangeable characteristic, the purpose or effect of which denies a benefit or puts a burden on such individual or group (Canadian National Railway Co v Canada (Canadian Human Rights Commission),  1 SCR 1114 at para 33).
Enumerated vs. Analogous Grounds of Discrimination
Section 15(1) contains nine “enumerated grounds”—race, national or ethnic origin, colour, religion, sex, age, and mental or physical disability. These grounds are personal and unchangeable characteristics. Laws that discriminate based on enumerated grounds violate section 15.
These are not, however, the complete list of actionable grounds. Enumerated grounds are merely examples of the types of characteristics that a discrimination claim can be based upon. Other grounds of discrimination that are not enumerated in s. 15(1) are called “analogous grounds”.
As with the enumerated grounds, analogous grounds generally have to be difficult or impossible to change. Sexual orientation, marital status, and citizenship have all been found to be analogous grounds. Employment status, marijuana/drug use, and membership in the military have not been found to be analogous grounds.
Intentional vs. Adverse Effects Discrimination
While a law or government action that purposely discriminates will violate s. 15(1), discrimination does not have to be intentional to be actionable.
Sometimes, a government action or legislation may appear to be neutral and non-discriminatory, but it causes a certain group of people to be excluded anyway. In this situation, the law is said to create an "adverse effect".
For example, legislation providing medical services may be neutral on its face, in that it provides all people certain medical services free of charge. Nevertheless, failing to provide sign language interpreters renders deaf people unable to benefit from the legislation to the same extent as hearing persons. The failure to provide sign language interpretation created an adverse effect on the basis of physical disability (Eldridge v British Columbia (Attorney General),  3 SCR 624 at para 60).
Section 15(2) allows the government to implement programs for the benefit of certain disadvantaged groups without facing a discrimination claim. These programs are not considered discriminatory because their purpose is to combat and reduce existing discrimination.
These programs are sometimes attacked as constituting “reverse discrimination”. Therefore, the government must be able to prove that the program has an ameliorative purpose (designed to improve situations for a disadvantaged group based on an enumerated or analogous ground). If the government can demonstrate this, the program can stand.
There are three questions that must be asked to determine if there has been a violation of section 15 (R v Kapp, 2008 SCC 41 at paras 17, 40-41, Withler v Canada (Attorney General), 2011 SCC 12 at para 30, Alberta v (Aboriginal Affairs and Northern Development) v Cunningham, 2011 SCC 37 at paras 42-45, Quebec (Attorney General) v A, 2013 SCC 5 at para 186):
Does the government action or legislation create a distinction based on an enumerated or analogous ground?
If yes, is the government action or legislation part of an ameliorative program aimed at improving situations for a disadvantaged group? The Court must be satisfied that the following conditions are met (Alberta (Aboriginal Affairs and Northern Development) v Cunningham, 2011 SCC 37 at paras 44-45):
a. There is a correlation between the program and the disadvantage experienced by the particular group.
b. The purpose of the program is genuine.
c. The distinction generally serves or advances the goal of the ameliorative program.
If these conditions are met, there is no violation of section 15. If not, the analysis continues and we must ask,
3. Does the distinction create a disadvantage by perpetuating prejudice or stereotyping?
A law perpetuate prejudice if it suggests a negative attitude or opinion about a person that is based on any of the enumerated or analogous grounds. This is also true of laws that give greater moral worth to certain persons at the expense of another group of persons on the basis of such a characteristic. Laws that create a hierarchy among different individuals based on having or not having an enumerated or analogous characteristic would also perpetuate prejudice (Quebec (Attorney General) v A, 2013 SCC 5 at para 193).
Stereotyping is attributing characteristics to members of a group regardless of their actual capacities. A law that creates a disadvantage based on a stereotype that does not relate to individual needs and merits is discriminatory (Withler v Canada (Attorney General), 2011 SCC 12 at para 36, Quebec (Attorney General) v A, 2013 SCC 5 at para 201).
If you think your rights under section 15 have been breached, click here for the second step in the analysis (s.1)