According to Eck Shattered's description, the rules were not complex.
Wizards could launch a "skill" or actively kill a person each night. If they chose to kill, they could not launch a skill;
If two wizards chose to kill each other the same night, or if one of the wizards chose to do nothing and skipped a turn, it was considered a stalemate, and neither of them would die.
Civilians could also kill.
If civilians fought each other, or the defender chose to do nothing, it resulted in a stalemate; if a civilian fought a wizard, or the civilian did nothing when attacked by a wizard, the civilian would die;
Only if civilians acted after the wizards, and the wizards had already chosen to attack someone else, could a civilian kill a wizard;
If multiple people tried to kill the same person at the same time, the kill would go to the first person, and the second would discover the body and be able to identify the killer.