I grew up playing with blow guns. We'd have wars, steal the flag, night games, and do a number of other things that I won't admit to. A decent shot would stick in your leg through a pair of Levi's and we'd always use eye protection. I'd guess that I've put 20,000+ darts down the tube.
I prefer to shoot blowguns with both eyes open. If only one is open it's hard for me to aim. The "double vision" of the barrel is close to the same spot when you look at the end of the barrel. So just imagine you've got a single front sight to work with. Obviously you have to compensate for drop and and wind more so than with a firearm. It's like a sniper. You estimate the distance and then make the necessary adjustments. It's a lot easier to shoot targets at a lower elevation because you don't have to make as drastic of adjustments. On flat terrain, you'll get the best range at about a 35-45 degree angle or so.
Try taping two of them together to make a double barrel (if your type of dart gun permits). 3 or more probably won't work. We've tried with every imaginable configuration above 2.
It's worth pointing out that our darts were made out of magazine paper (....and yes they would still draw blood). I can't say that I'd recommend dart gun wars with metal darts as they could really do some damage to soft tissue.
"Among the many misdeeds of the British rule in India, history will look upon the Act depriving a whole nation of arms, as the blackest."
- Mahatma Gandhi