Human social interactions can often be modeled as mixed-motive games, where cooperation and competition coexist. Although many studies have examined how people coordinate in purely cooperative settings, less is known about how individuals navigate severe, protracted conflicts to reach mutually beneficial settlements. In this study, we introduced a long-horizon territorial conflict game in which participants competed on a two-dimensional board by dispatching troops to expand their territory. Despite repeated interactions, conflict intensity did not subside over time—contrary to findings in simpler, one-shot matrix games. However, when a payoff-irrelevant color boundary was introduced, participants used this salient perceptual cue as a focal point for dividing the territory. The presence of this “territorial Gestalt” shifted strategies toward defensive postures, reduced the frequency of direct battles, and enabled opponents to settle conflicts precisely along the perceptual boundary. These findings extend focal point theory by demonstrating that humans naturally import external, payoff-irrelevant concepts into conflict situations to achieve coordinated outcomes. Our results highlight the importance of perception-based territorial Gestalt in fostering cooperative resolutions to otherwise intense and enduring disputes.