In keeping with the “Explore, Report, Cooperate” motto of the Starfinder and Pathfinder Societies, engaging in non-consensual character-versus-character conflict is prohibited. Players must obtain the consent of other players before taking an action that would intentionally include another Player Character in a damaging effect or other or harmful effect (such as effects that impose negative conditions).
Some examples include casting a harmful spell on another Player Character or an area that includes them, throwing a weapon with the explode property that would deal damage to another Player Character, or moving closer to another Player Character while surrounded by a harmful emanation in a way that exposes them to its effects.
This rule does not apply in situations where a character is not acting of their own free will, such as if they’re being mind-controlled by an NPC and forced to attack a fellow Starfinder or Pathfinder.