When you were a kid, did you ever play guns? What sort of rules did you use? What kind of toy guns did you play with? Did you have a different name for it other than just "guns"?
Usually we played with the light-up guns that made noises rather than Nerf guns. Nerf guns were cool when you had darts, but we lost so many of them that we didn't play with them much. We had some really big ones that were really cool. They don't make them these days like they used to.
My friends and I played it a bunch of different ways. Sometimes we did a deathmatch style game, sometimes had it was like hide-and-go-seek, and sometimes it was coop against a bunch of imaginary enemies.
When we did it deathmatch style, usually if you got shot, you had to lay down on the ground and count to five and then get back up. Since our guns didn't have any darts, it was usually just "I shot you! You have to get down!", which lead to more than a few arguments and debates.
Hide-and-go-seek style was like most other hide-and-go-seek, except more stealth was involved because they could just shoot you and you were out. I don't remember if you were ever able to shoot the person that was it, since it was a while ago.
Of course, coop was always fun. My friend's house had a layout that perfectly complimented whatever team of enemy ninjas or robots we were fighting, so we could always kill a few hours blasting away bad guys that weren't there.
How about you?