Board Thread:Questions and Answers/@comment-5105419-20131221162649/@comment-6697950-20131221192220

Volume 1: "Even then, they never «murdered» anybody —well, at least during the first year."

Volume 5: "However, this unwritten rule of «Not causing the HP to drop to zero» was broken by a strange player.

"This guy's name was called «PoH». It was a really funny name for a character, but unexpectedly— or rather, it's because of this that he had a certain charisma. [...] "A year after the game started, on the New Year's Eve in year 2023. PoH and company, who have grown to about 30 people, attacked a small guild that was having an outdoor party in the field at a viewing spot, and killed them all."

So, basically, no-murder-allowed was an unwritten rule that everyone followed until the LC was founded.