Check your local laws for a solid answer, but typicaly shooting your gun on private property is fine.
There are no laws concerning paintball in your backyard or other private land, however most commercial fields will have an age requirement, usually between 10 and 12.
It depends on where you are. There are shooting ranges in most U.S. cities, and if you live outside a city's limits, you may be able to shoot in your backyard, if it's safe and legal. Check your local laws.
No but common sense does need to be a factor. Obviously, an urban city like area would cause many problems. Though if you live in a wooded area, most counties do not care as long as you do not vandalize.
The Australian Book of Laws
It all depends upon the zoning and/or humane laws in your particular city.
By law, 18 to buy, under 18 you can be supervised by an adult to use them. But it is illegal for someone under 18 to take the marker off the premises without an adult. :)
if you live in an area where the houses are closer than 250 ft together you cant be shooting anything HPA or CO2, if you live on a farm its obviously not a problem :)
No There is not
It depends on the laws of your area.
If the children are not old enough to play at a certified field, then it is more than likely illegal. The average age for a field is around 10 to 13 years of age, depending on state or local laws. The legal age to purchase a paintball marker is 18, but can be used by a minor with consent.
its a marker, not a gun. So technically if there are gun laws they don't apply to paintball markers. Now if there were laws against painting, then no you couldn't. But then again the paintballs have biodegradeable stuff in them and are not considered paint. Are you trying to ask if you can expel dishsoap in your yard with a dishsoap marker? That's what it sounds like to me.