Having possession of any substance in Schedule I, II, or III is offence unless you have the authorization to do so. The most common substances in those schedules are: -marijuana -Hashish -Cocaine -Morphine -Heroin -L.S.D. -Oxycodone -G.H.B. -Psilocybin ("magic mushrooms").
A conviction for this offence will have severe consequences on your ability to travel outside of Canada. Most countries, including the U.S.A., do not permit many convicted drug offenders through their borders. A.R.E. Law may be able to formulate an outcome that is unlikely to restrict your ability to travel. However, the decision to grant you entry is at the discretion of each country's individual border guards.