Hear that fellow Stalker choking out a death rattle? Better run and help him - in this desolate world you need all the friends you can get, and fighting off the mangy dogs that are chewing at another man's face might open up some profitable new adventures. But with eight warring factions roaming the Zone, you're always going to be somebody's enemy. Approaching the military with your weapon drawn, for instance, is a recipe for swift suicide.
Above: Your neighbors aren't always friendly
Fortunately, though, this can also work in your favor. Take the soldiers who control a nearby checkpoint in your first area. You could pay them to pass through, or you could draw them off into a firefight with a wandering patrol of rivals, stepping back to watch the battle unfold before mopping up the weakened survivors. Stalker lets you do almost anything you want, but beware of making yourself a target for some serious payback.