Efforts to strengthen democratic institutions have become a nearly universal feature of peacebuilding efforts in states recovering from civil war, yet such institutions often become dominated by a single actor or party. Why are some post-conflict incumbents able to dominate politics in this way, while others face more robust electoral competition? This study finds that post-conflict electoral competition depends on the types of capabilities that combatants develop during civil war. Where rebels develop capabilities that can be converted from military to electoral use, incumbents face stronger electoral challenges, but the effects are conditioned by the number of actors involved.