In the United States, different localities have their own regulations:
Under Federal Law,
Airsoft guns are not classified as firearms subject to the Gun Control Act.
Orange tips must be present on the barrel ends of the airsoft gun when they are shipped in a manner that crosses state lines. Once you own the airsoft gun, you may not remove the orange tip, however, many people do and reattach it later.
Airsoft guns' trademarks must be removed where the manufacturer does not have an existing license agreement with the "Real Steel" gun's manufacturer in the US. (Example: Classic Army has a licensing agreement with Arsenal Arms, so the trademarks can stay on imported replicas of Arsenal's SLR 105 A1. In practice enforcement is hit or miss. You might get an "unlicensed" gun through customs with Trademarks intact, while a Licensed gun might be held in Customs by an "underinformed" customs agent.)
In addition, the similarity between genuine firearms and airsoft replicas is close enough to provoke interaction with local law enforcement personnel if an airsoft gun is carried openly in public.
If someone were to, for example, attempt a robbery with an airsoft gun, they would be charged as if the airsoft gun were a real firearm.
New York City has a total ban on airsoft guns.
Michigan restricts the purchase of these guns so that they may only be purchased from a licensed retailer.
All states require you to be atleast 18 years of age to purchase airsoft guns and pellets.