Got an odd idea based on semi-random encounters & would like to know what you think. It''s a bit long, but I''ve formatted to be easy to read...
Planned Random Encounters
You overlay a grid on a map. You then fill every cell on the map with numbers that represent possible encounters. The encounters are simply probabilities that get tested every time you move inside the cell.
The grid numbers are based on player actions, who the player is, and events going on in the game world.
Example: Red Faction is attacking settlements in a desert. They have a base in the NW corner of the map. The closer you get to the NW corner, the higher the numbers in the grid are. This means that you''re more likely to run into Red Faction the closer you get to their home base.
Also, every so often when you stop at a settlement, you have a chance to encounter an attack in progress.
Now, say you take out the NW base. All the numbers in the surrounding area for Red Faction drop. From the player''s point of view, Red Faction was crushed and scattered. They may, over time, concentrate in another area, however, and start up again.
Reactive: Making This Like an RPG Story?
It''d be great story (maybe) if Red Faction leaders decided to hunt you down. Now, you
could actually do AI that had the leaders moving on the map, chasing the player, getting into near misses, ambushes, etc.
But you''re not guaranteed to have a great story that way. RF leaders may miss much of the time. Or repetition may set in. Worse, the AI may not be up to handling all it needs to do to logically pursue.
What about simply spawning a wide number of set piece situations according to the cell the player is in? They''d involve a cast of familiar characters in different situations, be based mostly on player actions, be spaced out using timers to control for pacing (which you could ramp up or down), and lead to a very non-linear yet seemingly connected story.
Boot Hill 
The Red Faction leaders want a showdown at high noon. They''ve kidnapped the player''s best buddy, and are holding him hostage near the water tower. All the player knows is that his buddy is missing (a specific situation we triggered). When he goes into town for supplies, the RF leaders will be waitin''!
Ever notice all the coincidence that happens when a GM games an RPG or when a writer writes a story? People are in the right places at the right time, and everything happens for a good reason. We want to imitate this, but keep the all important sense of player freedom.
How It Might Work
Maybe the answer to this is simple:
- Create a huge bunch of possible situations. The situations correspond to things you can trigger (based on player actions, or NPC actions). They involve NPCs, actions the NPCs will take (could be a script), what the NPCs have, and where the situation takes place.
In our example, we''ve spawned a few NPCs with sniper rifles, a head honcho waiting in a saloon, some neutral NPCs that act as roadmaps, and the buddy bound and gagged in the empty water tower.
- Associate the situations with grid cells on the map. We only spawn things that make sense with the location. No Red Faction spawns, for example, if we know every Red Faction guy is dead, or that we''re in a place they could never be.
- Expose some (but not all) of the information to the player: For instance, if RF''s numbers are high in the town grid cell, a friendly NPC could warn the player. "Careful! I seen a lot of RF hombres lurkin'' about. Heard tell they was looking for you!"
- Every time the player triggers a probability, load the map with stuff then and only then (even if this is as simple as seeing a enemy hanging out). This cuts down on AI and managing what should be where.
- Give the player devices, allies, and information about what''s on the map (a spyglass to see who''s in the next cell, or warnings like the flickering of a campfire in the distance...)
- Be sure to let players get into and out of situations at will (like retreat, hide, evade) and make sure they can most of the time encounter situations only when prepared (meaning you might only hit them with a flood only if they had a boat, or whatever). This theoretically allows you to control game balance precisely, so that every situation is fine tuned and fun.
- Finally: Relate the situations to the past history of the game (say, like decrementing all the numbers for Red Faction after the base attack). You can keep a history of what''s gone on in the past, and this allows you to keep the player interested because you can vary situations.
You can even key in on player responses and bias situations toward what the player likes, assuming you can somehow determine this.
Why This Is Better Than A Story
Humans make patterns and draw conclusions. We can''t help but connect the dots. Given a random grouping of patterns, we''ll automatically see a shape if the information before us isn''t too confused and scattered.
The same principle might apply here. By having connected, semi-random, set piece encounters whose probabilities we can tweak, we gain both connected, seemingly logical events, a high degree of player choice, and replayability. We create the illusion of cause and effect, and if we present the info to the player (thru NPC conversation, skill use, etc.) in a good way, they may get the feeling of an overall story without the restrictions of little or no choice stories traditionally impose.
What do you think?
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Just waiting for the mothership...
Thanks to all the goblins over in our little 
