The California Penal Code defines battery as the willful use of force or violence upon another person. Generally, it refers to any kind of physical contact that the other person has not consented to. An assault is attempted battery.

The individual charged with the assault must be considered reasonably capable of carrying out the attack. The target of the attack must also be aware of the danger, though that is not always true. Along with carrying criminal penalties, assault is also a civil wrong, which means the target of an assault may sue for damages (such as bodily harm or mental distress) resulting from the attack.