The rules are simple: you start with 100 health, represented by 5 lights --- tag others from behind and avoid getting tagged.
Each time you are tagged, 1-20 health is lost (randomly). If you have 89 health, you will see that 4 lights (20 health each) are solid and the last light is blinking. Once you have only 80 health, the last light stops blinking. When your health is less than 20, all of your external lights start flashing --- indicating you are in critical health. If you happen to tag someone while in critical health, you GAIN 20 health and your opponent is critically hit. The game ends when you run out of health.
The game does not end when you lose all of your health, instead, you get converted to the team color of your opponent and start with critical health.
The goal of the game is to convert all opponents to your own team color.