The aim of the current study was to show that the type of conflict behavior (constructive vs. unconstructive) groups use in conflicts depends on their power position as well as the likelihood that power determines victory and defeat. In an alleged online debate, we created a conflict between two opinion based groups. We then measured participant’s action tendencies and their actual behavior. Overall, the results show that especially when the likelihood that power determines victory and defeat is low, power plays a role: those low in power become more constructive, while those high in power show no constructive behavior at all. Next to that, powerless groups tend to behave more unconstructively when it is likely that power detremines victory and defeat. The implications for intergroup relations are discussed.