Simulations of world history, like the real thing, are complex systems whose outcomes most often (if not always) constitute highly contingent events. Rarely (if ever) will researchers be able to find unqualified main effects that explain important outcome measures that affect the security and prosperity of the world community. The problem of contingency for testing hypotheses about the causes of certain types of outcomes (e.g., mass killing, starvation, economic collapse) from only a few simulations of history is discussed with reference to the Global Change Game simulation reported by Altemeyer (2003).