As long as you've informed the Rangers office and cleared the location with them it isn't a problem. I wouldn't suggest you try to play on a patch of crown land in your downtown district....try to pick an area that you can be very sure that you won't get many walkers or stray hikers. Most people will check in with a rangers office to see if it's ok to hike or camp in an area before they do so.
If someone does happen to enter the game area, I would suggest the person be greeted in a friendly happy manner, you should instantly turn in to an embassador for the sport and let them try out your weapon, marvel at the hardware and complexity of the game. Better the game stop for 15mins and try to recruit/inform a passer by then get angry and give them a reason to try to kill the sport.
I know most people would consider the above embassador suggestion to be common sense.....but for some, it may have to be stated.
On the seventh day when God rested, we overran his perimeter and we've been running the show ever since....