Simple assault charges are usually misdemeanor criminal charges filed against a person accused of an assault that resulted in minor or no injury to the victim. State laws vary, but often simple assault can be anything that causes a person to fear imminent bodily harm.
Assault usually requires some physical action, such as raising a fist or walking toward the victim in an intimidating manner while verbally threatening him. In most states, it also includes actions that do cause actual injury, such as battery with fists or with a weapon. Some states differentiate between assault and battery, but most do not.
Simple assault can be contrasted with aggravated assault. Aggravated assault refers to serious assaults or assaults with legally aggravating factors. This usually includes serious injury that requires hospitalization or cosmetic surgery. The presence of a weapon is also usually an aggravating factor, even if no injury occurs. Some states also have special laws protecting vulnerable individuals including children and the elderly, so an attack that might be a simple assault on an able-bodied adult becomes aggravated assault if it is committed against a protected class.
Simple assault charges are generally based not only on whether the victim felt afraid but whether that fear was reasonable. In cases with physical harm, charges can even happen if both participants agreed to the fight and were not afraid.