There are very specific rules on where your assets go if you die intestate (without a will). In Ontario, these rules are contained within the Succession Law Reform Act. Essentially, the government uses a rigid set of rules to determine your next of kin and distribute your assets accordingly. (And remember: a common law spouse is not in the line of succession in Ontario.) If you have children under age 18, their shares of the assets will be held in trust by a government agency until each child turns 18, at which point they will inherit their shares. If your wishes involve any gift that falls outside of these rules, you need to have a valid will in place.