Just finished writing an article about guerrilla warfare. I will spell check latter. I'm also working on another article talking about new idea i have about open world gaming environments.

Here, thats it. I think this is how at least one FPS should be played as:

You are an insurgent in an enemy territory. And you literally have to sneak around and plan your attacks all of the time. And you also have to add escape routes into your plan, in case things turn out too dangerous to deal with. By the way, nobody is telling you where that escape route or enemy is, you have to find out it all by yourself by observing the surroundings. Also, the game should be mainly based around a free play and have very little of the typical "go there, this needs to be done" type of missions. If any.

I also would like player respawning in this kind of a game, instead of 1 life policy. So you can't just unmake your failure by simply reloading game from a checkpoint/save file. Bad calls have premanent consequences and you are stuck with them. Yes, you may be able to save game all of the time, but you can't quit without saving. So no undo button, lol. There also has to be a harsh penalty for dying. So you can't just die, respawn, rush back to battle, die again, respawn again, repeat. One possbility is death = losing all the gear. And remember, better the gear = harder to get. You could easily spend hours to get your hands on some good sniper rifle, or a good camo suit or armor for example.

One example of rare equipment would be something like 5 cm Granatwerfer 36, which you can carry around, deploy and actually fire at hostile targets. But remember, once you deploy it, you can't just pick it up and run away with it like in Far Cry 2. If you have to immediately leave, its on your own if you want to risk taking time to pack it, or leave it there alltgether. It also weights a lot, so you can't move very fast with it. But you should be able to carry ammo and weapon separately. For example, you can move some mortar rouns to a certain hidden place first and then carry your mortar after. Then take your ammo from hideout and start laying some waste on opponents. But be wary, enemies might easily return fire once they figure out where are you shooting from.

Sometimes it is possible to re-gain your lost gear, if lets say nobody has found your "past life" body before you do. You respawn always like day or longer after your death, so its not sure if your stuff is still there or not. Enemies should mainly pick up your gear and often they will start to use it. Sometimes when you die, you take your enemy with you, so nobody might not know where your body is. Or if you get killed by unlucky mortar shot, fired blindly at the places, where they think you might exist. To your relief, you don't have to wear all your stuff with you. There has to be some secret "safe houses" around on the map, to store your important stuff. Here is example of hidden bunker used by anti-soviet resistance after the ww2.
example hideout:
http://upload.wikimedia.org/wikipedia/commons/b/b0/Bunker_of_lith_partisans.jpg

These bunkers were built as hidden safe havens for anti-soviet resistance movement, but i bet
every resistance have used a hideouts. Yes, there was a guerrilla war against soviets from end of WW2 till the mid 50s troughout the Eastern Europe. The resistance started immediately after soviets had occupied the territory and ceased slowly by the mid-50s.

Another idea, is that you don't play for "objectives" as much as you play for "kill score". Well, the main objective of any forest brother (insurgent) is to wear down its enemy. And you wear them, by taking out its troops, by blowing up theyr equipment, bridges etc... If resistance is stronger, you raid some of theyr smaller outposts. Weaker resistance usually fights a defensive battles. So you should never run from one objective to another like in Far Cry 2 or worse - in Red Faction Guerrilla! Sometimes all you do, is sneak close to enemy patrol or outpost, take out few guards and run like french :P I think weapon stats should play important role, like individual weapon stats, kills, shots fired etc...

And don't forget, gameplay can never beabout smashing trough a main gate, killing whole army in 2 minutes and and then completing your "objective". Maybe you kill some more on your way out or not, but eventually you get your ass out of there and win. I think its important to actually add in an outposts, lets say military bases and some other locations, that are so heavily defended that you either never really "capture" them, or you do that after a series of hit and run raids. But attacking some most of the outposts head on is as good as suicide, especially bigger bases. Besides, enemies can call in reinforcements, they also conduct a large scale raids sometimes.

Finally, enemies should never just pop into existence out of nowhere. They have to travel in from outside of the map. That could also generate some traffic. Because some travel around in trucks or come in from a train. A traffic also has to cross places such as bridges. And bridges can be blown, if you can get past the defenses. Another thing, is enemy would have some traffic anyway, either its convoys passing trough the country or patrols within the country itself.

Finally, this game would take extreme amount of resources to render, as all of the enemies troughout the map should be counted all of the time. In no way NPCs should be generated out of a thin air like in Just Cause 2. There has to be a clear picture of how many units there are, what are they doing and that troughout the whole world. Even if they are not directly rendered, they should be there. Altlrough i didn't mean, that player knows where everybody is. I meant, that computer running the game should know. As in some games, such as Just Cause 2, NPCs are randomly generated after you reach to certain area and rest of the world practically has no NPCs in it at all. Only the areas, where player currently is.