Though it is against the fundamental philosophy of Frontiers to legislate such mortal matters from the administrative level, allowing mortals to handle the problem of player killing proved unmanageable due to the fact that a few people took it beyond the gaming spirit of Frontiers and made player killing a tool of personal malice.
What matters is intent. If it is clear that you planned to kill another player, then you will be repremanded. If it was clearly an accident, and all players involved agree it was one, then no charges will be filed. Attacking a player is considered playerkilling.
Limited player killing is allows in regions marked as arenas. They
may be single rooms or entire areas.