An act of god is a term used in contracts and by insurance policies to represent any natural disaster outside of human control, aka floods, volcanoes, hurricanes and other such related events. As the term is used rather broadly, it can be sometimes be difficult to know what exactly comes under the term Act of god, and how it relates to particular fields; like car insurance. Insurance policies differ vastly, especially concerning automobiles, yet most car insurance quotes will cover this under comprehensive insurance.
Although the early definition of an act of god was an event which no amount of human foresight could prevent, the most common definition is a naturally occurring event beyond human control. The exact events that are covered in a car insurance policy will differ from state to state, and with different car insurers. More or less, 'acts of god' refer to natural disasters and similar events.
Some insurance policies cover natural disasters in their comprehensive insurance packages. However, some car insurance companies may have a clause that states that comprehensive coverage will not cover an act of god. These companies usually require an extra coverage to be purchased (called 'Acts of God insurance) in order to receive this protection. As there are many different car insurance options available, many pick and choose what types of coverage they want, according to the required minimum, as well as concerning what they feel they need protection against.
Acts of God include, but are not limited to; floods, tornadoes, earthquakes, heavy winds, hail, snow, damage done by falling trees and even damage done by animals. In some cases colliding with a deer (a very common occurrence in some states) is only covered by collision insurance. For the most part, however, this is considered an act of god, and will be covered by comprehensive insurance. However, there are some exceptions, in some states which have a frequent number of, for example, deer collisions, insurance companies will not cover this under normal car insurance quotes and may require additional coverage in order to be protected from this.
It is also worthwhile to note that heavy rains may be an act of god, however, should you decide to drive during such an event and have an accident; you will not be able to file it as an act of god. The main distinction is that such claims do not count as a strike against your driving record, and should not increase your premium (read the fine print for details). Each insurance policy may have a different definition of an act of god, so it is a good idea to consult your state insurance regulators as well as the insurance company.