1. Corin Anderson Eric Anderson Geoff Hulten Tessa Lau
AI in FreeCiv
Corin Anderson
Eric Anderson
Geoff Hulten
Tessa Lau

2. Our Goals
Don’t rely on AI’s authors’ knowledge of the game -- learn own strategies
Apply “real” AI techniques

3. Our approach
Create a controller for each game element (unit, city, region, army, …)
Each controller uses some form of AI
Planning, constraint satisfaction, heuristics
Different controllers may use different techniques
Organize controllers in a hierarchy

4. Controller hierarchy Master Controller Army Controller
Region Controllers
non-mil units? all units?
only military units?
City Controllers
should cities boss units around?
Unit Controllers

5. Jobs and tasks Corey Eric Tessa Geoff
Army transport controller ; architectural glue
Eric
City controller ; controller / controller interface
Tessa
City worker allocation ; UI
Geoff
Master control -- top-level control

6. Defining the interface

7. Example: Settlers

8. Other examples of three-phase interface

9. City worker allocation
Server-side suggestions are okay
But what about maximizing global requirements?
Global science, money
And what about neighboring city interactions?
Land square contention
Constraint satisfaction ; integer programming

10. Army Controller Troop transportation -- a logistics problem
Solutions attempted using planning
LPSAT: Metric information, such as unit hitpoints, attack value, etc.
TGP: Task duration, such as turns to move
Showing promise, although some difficulties
Really want LPSAT + TGP. Ideas??

11. Master Controller Approximate FreeCiv with a simpler game Regions
Level of Development
Level of Exploration
Gross Terrain Features
Armies
Estimate of total offensive/defensive power
Location

12. More Master Controller
Simple Actions
Armies
Move to region (aggressively or passively)
Regions - perform a number of actions equal to their development
Grow (target region, can be itself or adjacent)
Build Army (target to add the units to?)
Explore (target region, can be itself or adjacent)
Research
Evaluation based on development & army size
Perform state space search every N turns
The effect actions can be hard-coded, learned across games, and/or tuned during the course of a game.
The output of this is fed as suggestions into the region and army controllers, does this conform well enough to our suggested master/slave interface?