PeaceTreaties is a concept geared towards a smaller, more vanilla Minecraft server that still supports an in-game economy, commonly featuring players engaging in combat. If a player is about to die in combat and combat-logging breaks the server rules, they could make a "Peace Treaty". A Peace Treaty attempts to pay the attacker a server-configured amount to avert combat and teleport back to the spawn, where there would most likely be no PVP. Of course, the attacker could always just refuse, leaving the two players to go back to fighting.
As a Spigot plugin for Minecraft Spigot servers, it provides an alternative gameplay mechanic, should the server be interested in the concept.