Quote:Original post by Trapper Zoid
sunandshadow, since you come from a literary background, can you describe the basics of how you would design a story generation system?

Sure. I'll try to sketch out the text-only generated interactive story game I was saying we should aim at. I also want to point out that I don't think it would be too hard to switch to a graphical interface after the game worked in text mode.



Okay, you turn on the game. Here are the steps the program has to go through to make the game happen:

0. (Optional) Gather input from the player which can be used to customize the story generator's output to the player's taste.

1. Spawn a fishtank (enclosed 3D area) which will be the stage for the game or the first level of the game. Spawn the PC (or multiple PCs for a multi-player game I suppose). Good default placements might be the middle of tank floor, one end of the tank, one corner of the tank, etc.

2. Run the Story Generation Engine. This involves consulting the player's preferences if known, and accordingly choosing a setting/genre for the game, choosing one or more Goals which will signal the end of the first level/chapter, choosing Obstacles and methods for overcoming these Obstacles, etc.

3. Spawn the Goal(s), rooms/walls, NPCs, tools, etc. called for by the engine, making sure the Obstacles are in between the PC and the Goal(s), and any tools necessary to overcome the Obstacles are in between the Obstacles and the PC. Random objects such as trees and monsters may also be spawned now.

4. Communicate to the player the initial equilibrium of the setting and how it is disrupted by the initial incident. This can be done in several ways:
- A. The PC witnesses the initial incident as it happens.
- B. The PC recalls the II as introspection.
- C. An NPC directly tells the PC about the II.
- D. The PC eavesdrops on NPCs discussing the II.
- E. An omniscient Narrator describes the II.

5. Control of the game is released to the player, who explores the PC's immediate surroundings. This may include encountering and fighting enemies, talking to NPCs, solving puzzles, acquiring and using objects (including money), playing mini-games, and managing equippage. In the course of all this the PC encounters Calls To Action and Hints. The first call to action (aka telling the player a Goal to pursue) may optionally be delivered along with the initial incident. Other than that, these bits of info may be delivered by means of NPC dialogue, finding written info objects, finding physical clue objects (with accompanying introspective interpretation), and introspective error messages when the player attempts an action that doesn't work. This is the Rising Action phase of the plot.

6. The last Obstacle standing between the PC and the Goal is the Climax, and may be made more dramatic by being a particularly complicated or dangerous Obstacle, emphasizing the nearness of the Goal by one of the methods listed in step 4, having the villain NPC (if there is one) taunt the PC, and/or dramatic music.

7. When the PC obtains the Goal (note that in certain games this may include the PC's death at the end of the game) it is essential to praise/reward them in some way, and to either communicate that the initial equilibrium has been restored/repaired if the game is over; or if the game is not over, present them with a portal to the next level/chapter and repeat this process from step 2 including communicating a new goal.

I would call my version Freytagian rather than Propppian, but I suppose my own mental model of plot grammar is informed by Propp as much as anything else.

I'm going to read Chris Fairclough's thesis, looks fascinating, but it's 200 pages long, so not tonight. ;)



Mainly I am posting now because I wanted to remedy a major omission in my previous post: I didn't talk at all about how the NPC AI supports the plot interactivity. There are three seperate difficulties of NPC AI design:

1) Dialogue generation (which is also an issue for narration and introspection) is probably most practically addressed by an Eliza approach.

2) Information control (knowledge differences between NPCs, ignorance, rumors, learning from conversation, and NPC item posession could also be included here) is probably best handled by Venn subsets in a SOAR knowledge database.

3) Emotional/personality modelling requires a map of all possible personality states and numerical gauges which determine the NPC's emotional state and how that emotional state is affected by various inputs.


If those difficulties could be overcome, and adding the standard problem-solving type of AI, I believe a very realistic social gaming experience could be created by assigning various NPCs different personality types, starting emotional stated, esthetic preferences, and their own Goals at cross-purposes with the PC's Goal.

While that is a good start...you've merely come up with randomization.
What we're working towards is a dynamic structure of storytelling that creates itself and recreates itself based on interaction and reaction, as well as npc needs and context.

Umm, Ketcheval... what the heck would be the point of that? Aside from the fact that it would be horribly boring to play, non-dynamic story generators already exist. The whole point of this discussion is formulating an approach to creating a _dynamic_ story generator because we don't have a good one yet.

Exactly. We're needing something waaaaay more than just random.

In our case we have large NPC groups with needs/goals and individual NPCs with needs/goals. On a crude crude level, these needs will create quests for players to accomplish. Then of course that automatically creates a sub-level of how one NPC can help a player fulfill another NPCs need. Depending on what modifiers you introduce, the outcome of the quest attempt can be anywhere from success, partial success (including success in time for x,y z), to failure...which in turn creates a shifting set of needs...with resulting quests.

Ive re-read that and Im thinking to anyone but me it sounds like gobbldegook.
Here's what I mean.

Your character finds a computer in an abandoned facility and uses his hacking skill to determine when Faction X will be dropping a shipment of XYZ at the doc.
Earlier you had been asked to find this shipment by NPC Y. If you can get this to him in 24 hours then he will give your guild the blueprints for EFJ weapon.

Lets say you raid the shipment with your group and take it over successfully. This means that Faction X will offer quests to a) hunt you down b)go find another shipment of cargo XYZ and c) be unable to equip their troops with the ammunition for EFJ weapons. NPC Y will now be able to sell XYZ at his merchant tent and his standing in the NPC world will increase/change. Perhaps he decides not to sell to mutants because some other NPC asked a mutant player to steal the EFJ back from him.

Thats not even a very detailed version...but its not really random at all. Its dynamic and it has a dynamic effect on the capabilities and quest offerings of multiple NPCs and the player world.

Such a thing is do able...and the first to do it well will be hailed as a groundbreaking game.