Sixty-four sibling dyads (4-12 years old; 61% males; 83% European-American) were asked to resolve an ongoing conflict. Older siblings provided leadership by suggesting, modifying, justifying, and requesting assent to plans for conflict resolution. Younger siblings countered and disagreed, but also contributed to planning and agreed to their siblings' plans. Compromises were associated with first offers that met both children's goals, future-oriented planning, and limited opposition. Win-loss outcomes followed offers favoring only one child and arguments over older siblings' plans. Conflicts were unresolved when negotiations included frequent accusations and opposition, but little planning. Thus mutually beneficial conflict resolution required that children shift focus from debating past wrongs to developing plans to meet their unrealized goals in future interaction.