One more thing an infantry simulator ought to have: no fourth wall. In the first person view, most shooters give the appearance of perspective without the reality. That is, it appears that your rifle projects in front of you, but in fact it is a two-dimensional projection which only occupies the vertical plane of the monitor screen. This makes handguns and all forms of melee combat fundamentally obsolete. What is the real reason that soldiers carry pistols? Not because they're afraid that they might run out of ammunition for their primary weapon! If that were the case they would replace the pistol with extra clips for their rifle. No, soldiers carry handguns because they're handy, because rifles are long and unwieldy in indoor situations, and there are some cases when you cannot use them (e.g., when you are toe to toe with your foe). If an infantry simulator gives me a rifle, I want it to exist as an object with the proper dimensions in the world. If I run into my foe I shouldn't be able to shoot him with that weapon. Similarly, suppose I am a man with a knife facing a man with a rifle. I should be able (assuming he doesn't gun me down, of course) to run up to him so close that his rifle is worse than useless, leaving him at the mercy of my knife.