Social dilemmas are settings where the interest of the individual is at odds with those of society i.e. overharvesting in a fishery, not contributing to a public good. These dilemmas are widespread and take myriad forms with public goods and common-pool resources being the most prominent ones. The purpose of this dissertation is to examine how individual behavior is impacted by the presence of uncertainty in public goods and common-pool resources. These dilemmas exhibit two types of uncertainty, strategic and environmental. Strategic uncertainty refers to uncertainty about the actions of other individuals facing the dilemma i.e. will other individuals contribute to the public good or not. Environmental uncertainty pertains to uncertainty about the characteristics of the dilemma i.e. is the resource size large or small. While strategic uncertainty has been extensively examined, the existing research on environmental uncertainty is limited. Since the social dilemmas in the real-world are often marked by environmental uncertainty, policy-makers need to know how individual behavior in social dilemmas is impacted by environmental uncertainty. The dissertation utilizes laboratory experiments to study the issue because laboratory experiments allow us to implement different forms of environmental uncertainty, which would not be possible in the field.