There are three versions. All games are played with rubber-tipped suction cup type dart guns. When we play the guns are hard to find because everyone is buying them up.
The first version we tried was played just like the paintball capture-the-flag style with one flag in the middle in which you have to get the flag and advance it to their base (called "Football" Capture-the-Flag). You'd divide the youth into two teams and put the flag somewhere in the middle of the playing arena. For us the flag was placed in the sanctuary which was great for people sneaking around the balcony and amongst the pews.
You had to get the flag and hang it on a pole or something at their starting point or base. If you were hit by a dart, you were out of the game completely and would have to wait until next game. There is also a 20 min. time limit. The problem is that with most lights out you couldn't see nor often feel the darts hit you so there was a lot of fighting over if someone got killed or not. So much so that we abandoned this version.
The second version is similar to the "Assassins" game that some people have played. Let me explain the correct way to play first. The only difference is that in the real Assassins game you can't have any witnesses see you shoot your victim. This means that no one can actually see you shoot them. They can be in the same room but just not see it. We used to play this in college and the game lasted a whole month. This version is played continuously over days, weeks or longer depending on amount of people and how fast they kill and if you impose any time limits or killing quotas. It's good to include rules like no killing during school, at someone's employment nor during a youth or church service. You basically have everyone that is playing write their name down on a slip of paper. Then you hand out everyone's killing assignments.
Each person playing has no idea who has them but only who they have. You are only allowed to get the person with who's name you have and can't get the person shooting you for defense. After you get a person, you have to prove you had them by showing them their name on the paper, then they have to hand over the name of the person they were supposed to get and that is now your next assignment. So eventually the number of people playing will get smaller and smaller until there are two people hunting each other and one person finally prevails. You have to arrange the names that you hand out it in such a way as to make a circle so that as each person gets shot the circle gets smaller and smaller and the game continues. Got it?
The GOTCHA version we played was the same thing but in a shorter smaller scale. There could be any witnesses and there were the boundaries inside the church that we played. I would set up the names, hand them out and give five minutes for everyone to disperse and hide in the church until I blew the whistle. Once I did this they hunted each other down. With around 15-20 people the games were usually over in 30 minutes. Some people hid and waited for their prey to pass by or others hunted. It was a blast.
One warning. I would encourage using the term GOTCHA and avoiding language about killing, etc.,... We claimed that GOTCHA stood for "God Orientated Thought Changes Hearts Always" and said that we were killing with kindness, etc.