Coverage is a fundamental problem in robotics, where one or more robots are required to visit each point in a target area at least once. While all previous studies of the problem concentrated on finding a solution that completes the coverage as quickly as possible, in this thesis I consider a new and more general version of the problem: adversarial coverage. Here, the robot operates in an environment that contains threats that might stop the robot. The objective is to cover the target area as quickly as possible, while minimizing the probability that the robot will be stopped before completing the coverage. The adversarial coverage problem has many real-world applications, from performing coverage missions in hazardous environments such as nuclear power plants or the surface of Mars, to surveillance of enemy forces in the battlefield and field demining. In my thesis I intend to formally define the adversarial coverage problem, analyze its complexity, suggest different algorithms ...