Battle Royale
Battle royale is an absolute emergency status where the station failed to keep a civilized state and every character is on his own trying not to die. Often times this turns into a massive carnage with dozens of casualties and three possible outcomes: a very traumatized small group of survivors calling the escape shuttle, the last man standing achieving a moral win and then maybe escaping (or just committing not alive) or the complete destruction of the station due to some nuclear, plasma or just reset map attack.
Preventing a battle royale
Battle royale is often prevented by the combined forces of the janitor(s) and security with the first one keeping the station clean of blood and chaos related things and the second keeping it clean of the men who make them in the first place.
What to do'
Unless there is a serious reason to start killing people (like being a traitor or being attacked by one), you should never try to kill people in the hysteria of a battle royale, instead the best course of action should be to keep yourself out of danger (run if needed), get people to help you survive (combat is seriously number oriented if there aren't any traps involved) and try going back to work when chaos starts to go down. If chaos rises too much though, you should consider calling the emergency shuttle if it hasn't been called yet.