Talking about enemies is one of the most obvious crossover between game mechanics, story and art. All of them are equally important to form a good antagonist, that is fun. To me, it also means the disciples are influencing each other as well.
Minerals of Plot
I've read the guide to bad plots(http://www.ansible.c...le/plotdev.html), I tried to not use plotdevices, but I almost have to have at least one in a game like this, I just can't get anywhere without one. BEHOLD: The Minerals of PLOT!
I cleverly call it Diabolite. The name is not the greatest of all, I know. I am likely to change it when I find a better one. For now, it will serve it's purpose.
And since I am already writing about names that are subject to change, I let the humans call the enemies "the Horrors". The name doesn't satisfy me either, it is a better way to refer to the antagonists than "the enemies" or "monsters" I presume.
But back to the Diabolite:
the minerals come from far down under the earth: Natural Diabolite grows in a crystal shape. Even in it's unrefinded state, it is a valuable resource for both the Horrors and the Rising Sun. The Diabolite crystal is remarkably sturdy against most steel alloys. It tends to enclose precious metals like Titanium, Gold, Cobalt, Palladium and sometimes even Platinum that can be retrieved by refining the mineral.
But it's main application is to serve as a source of power for the humans as well as the horrors. Since the invasion, the humans have almost no other powersource left.
For the Horrors, it is more accurately described as a nutrition, the more primitive Horrors seem to feed on the raw Diabolite, while refined Mineral is eaten by the more intelligent creatures. Either way it is the only thing left after defeating one of the Horrors.
More on the mechanics side:
Diabolite is the main mineral of the game, the player needs it at LEAST to buy ammunition. Maybe I will do more with it once I give more thought into the Items/Skill system.
The weapons of the later game mainly use high performance ammunition. While effective, using them is also expensive, using it against a weak target is essentially wasting resource.
From a design standpoint, I always knew I wanted two groups of enemies. One group attacking with melee and one attacking on long range. A team of players has to use a completely different strategy for each group. While dealing with long range attacks, each player should dash from cover to cover and trying to provide cover fire. But fighting against fast, melee enemies it is generally saver to stay in a open field and take them out when they run towards the players.
I also played a bit with Ghouls, Zombies essentially, in my head. They never seemed to really fit. By fleshing out the resource idea, they suddenly make sense: Ghouls are the resource eaters, plus they potentially alert the more dangerous enemies. They themselfes are not a real threat, but a group of ghouls at the right time at the right place can change the situation.
The long range enemies are represented by the "demons", generally humanoid creatures that are also fairly intelligent and are able to form teams, flank and ambush the player.
Close range and let's call them 'special purpose' enemies are called 'Nightmares'. From an evolutionary standpoint, they don't make sense at all. Most of them are fast and vicious opponents, although most of them are not very intelligent. But there are some Nightmares, the humans call them Overlords. Alone, they are no threat whatsoever, but they seem to be able to control the simple minded Nightmares and let them attack in packs, wait for the player around the corner, flank them from behind etc.
The Horrors are now in a very raw state. I will carve them out in a later entry. I need a crude idea of what the Horrors are and what they can do, so I can think more about the overworld strategy.