S.T.A.L.K.E.R., part two

Is there any scripting at all in the game, is it all left to artificial intelligence?

Yavorsky: Let's talk about the storyline content, combat AI, A-life and how they interact with each other. The storyline content is the events the player must see to get the understanding of what he's doing in the game, what occurs around him, what is the Zone and what's his goal. The basic logic of the storyline content is pretty much predesigned - the starting conditions, key spots and the ending conditions. In terms of classic level, these scenes may not be called scripted, though. What's fixed is only the beginning, the end, and the condition at which the scene is considered accomplished.

The NPCs, however, are not glued to their places and may leave their position in case of danger and pursue the player, then return to defend the area if they failed to locate the player. You may also approach the targeted area from any side, wait and see how the area is protected before attacking it, try different assault tactics. You may rush, outflank, climb on a building roof and attack from there, you may sniper the target out from afar. The NPCs' AI is non-scripted, so you may expect their adequate reaction to different play-through tactics.

While the focus is made on storyline component during the first play-through, A-life co-exists with the storyline contents. Once a story scene is accomplished, it opens up to A-life and gets filled with A-life-driven characters through time.

Let's take a stalker camp, for example. The A-life is able to 'call for' stalkers in the Zone and assign them their roles: 'you are going to be in charge of the camp command, you will be a guard, you - playing guitar at the campfire, you - a storyteller at bonfire' and so on. After that the A-life sends NPCs onto 'works' as prioritized for the location (i.e. hunting mutants, collecting artifacts and so on).

In case the camp participants get killed, the A-life redistributes the works among the remaining ones, but where there's a big shortage of participants, the A-life will get back to looking for stalkers/monsters passing by to arrange a new camp, lair etc.

By playing the game through and accomplishing story quests, the player frees up more and more space for specifically A-life content (i.e. a bigger part of the game becomes fully randomized). Return to any of the previously accomplished levels in a couple of hours to see that the level is now filled with different content, and each player will get his own unique one. And thus get a unique experience.

Notably, the secondary quests the player may pick up are also generated in accordance with the way the A-life events develop.

Although it took us a lot of trial and error process to integrate the fully random A-life with the predetermined storyline in the game, we couldn't be happier of the result obtained.