Gonna be flat out honest, Yes a town or police may get involved but it hasn't happened in a while in my experience. Your fathers concerns are valid but are very unlikely to occur.
Usually, they go on their way, just check out the war. That has happened a lot, and the outcome usually is dictated by how you approach and deal with the situation. In the NorthEast, we're very polite, we talk to the officer and usually they end up leaving, sometimes they're cool about it and in my experience, an officer really liked the blasters and thought they were cool.
However, you may run into instances that the police are there to remove you. That has been the worst case scenario, they ask you to leave. Nobody has had guns drawn on them, (by the police) nobody in this hobby has gotten shot and nobody has had anything worst than being asked to move.
This is due to the approach, and what is going on. If a bunch of casually dressed guys with nerf blasters are running around, it looks better than people running around with camoflauge/military esque BDU's, excessive tac gear and real rifle replicas. There's a reason you're not supposed to dress tactically, and it's to prevent scaring people
For rest of a town
You're a lot more likely to run into civillians. Now reguarding property, you play on state property, don't ever play on someone elses because that's trespassing. Usually, most people don't care, you may get the angry parent or anti gun activist complain about how you're promoting violence but they go away if you refuse to interact. If you get someone who maintains the property, they may ask you to leave or what you're doing and you would have to go either way.
I find it funny your dad said in this day and age. Police getting involved are statistically low, we've been doing this for a while and our guidelines minimize the chance and interactions with police ten fold. Next, we play in areas harder to see from the public, because we're "out of sight and out of mind" so walled in parks or far away from public view or a highway is ideal. Property, state property is open to everyone and nerfing isn't illegal. Medical liability issues. Be smart and you won't get hurt, haven't seen anything outside some cuts at wars, there is the very real potential of blinding yourself if you don't wear eyepro but chances are slim. You can always fall, but use common sense, don't jump off of shit, you're responsible for yourself. Attending a war does not make the host liable because you chose to play, you need to look out for yourself. (I always carry a first aid kit just in case too, but for scrapes) A lot of these issues have been pre thought out in advanced.
TL;DR we keep our public interaction slim by being secluded and having safety measures like brighter blasters and clothes, police either check up, and may ask you to leave or may go. Civilians may see what's going on, they may ask you to go. We go if we are asked, we play on legal property, nerfing is not illegal so it is ok, and you are responsible for your own health safety, so don't be stupid.
Edited by Snoop Doggy doge, 26 June 2016 - 10:16 PM.