"You will not kill to kill, you will take the materials from the beasts you defeat. If you are found to be killing to kill and entertain yourselves, the ruler of this dungeon will kill you." This rule was abnormal, but if this was what the Nebula citizens had to follow to be able to sue this dungeon, then so be it. No one felt that this rule was ridiculous.
"Do not attack the ruler or the ruler's children. You will know them when we see them." This was a harder rule to abide by. However, if it was so easily seen that they would know, Clark did not care. He also had the analysis of the system. That meant that he would have the advantage of being able to see the hidden information. Specifically, if they were children of the ice dragon here.