You can kill children in Fallout 2. There's nothing stopping you from beating them in the groin with a sledgehammer or blowing thier heads off with an automatic shotgun. To stop this, the kids' onscreen presense, and thier sprites, were removed from the European version of the game. You can still see the things they say, but you can't interact with them in any way.
The first time I played it, I wondered what the fuck was going on in a lot of situations. I wondered who was talking to me in Klamath. I wondered where my stuff was going in Den. There's kids who stand by the doors of stores and pick your pockets as you go by. There's at least one quest where you have to find a lost child, which is pretty fucken difficult if you can't see him. I found a patch that puts them back, though. So lookout, kids! I got a sledgehammer with your groin's name on it.