LifeMC allows you to implement a complex life system into Minecraft. Every new player will start out with a default amount of lives.
When a player is out of lives, he or she will be banned until that player regains a life. Players can pay eachother in lives.
Download on spigot at: https://www.spigotmc.org/resources/lifemc.81758/
LEGACY release on dev.bukkit: https://dev.bukkit.org/projects/lifemc