Resources!

Nothing makes it easier to spark conflict than to have something someone else needs, or to need something someone else has. Opposing ideologies can also spark conflict, but rational thought and a player's understandable desire not to lose their character, if it can be helped, can make it more subdued than desired.

Sure, you can negotiate for resources. You can try to play nice and share if it's not a single artifact of great power or the services of a master of the arcane. But other forms of constraints - time, orders from superiors, personal grievances - can make typically peaceful approaches just as intense as all-out war.

Does your game need to pit two factions against each other, but you're still not settled on why they should be fighting? Here's a few suggestions:

• Both sides claim an artifact (however powerful or mundane as you want) has religious or historical significance to their people.
  
• One side holds a monopoly on a certain art, substance or technology that has the potential to dramatically alter the other's quality of life.
  
• Both sides want the political, religious or social clout to accomplish some goal, and must compete for support from a number of prominent figures.
  
• Both sides have a common foe, and their leaders have agreed to work together, but neither side approves of the distribution of power, food, knowledge or shelter, feeling the other side "has it better."

While you can certainly assign alignments to sides - good vs. evil or law vs. chaos - it might provide more depth and intrigue to break the mold. Next week I'll tackle Good vs. Good.