Item from Death Note by Tsugumi Ohba
Light's most devious insurance policy — two fabricated Death Note rules that cleared him and Misa of suspicion and derailed L's investigation.
Light's masterstroke of misdirection. He had Ryuk write two fake rules into Sidoh's Death Note: 1. **The 13-Day Rule:** 'If the person using the Note fails to consecutively write names of people to be killed within 13 days of each other, then the user will die.' This cleared Light and Misa — both had been confined for over 13 days without writing names, and they didn't die, so they 'couldn't' be Kira. 2. **The Destruction Rule:** 'If you make this notebook unusable by tearing it up or burning it, all the humans who have touched the notebook will die.' This prevented L from testing the 13-day rule by destroying the notebook. Near eventually proved the rules were fake, but only after L's death. The fake rules bought Light years of freedom and were arguably his single most important tactical decision.
Written in the same script as the genuine Death Note rules, indistinguishable from authentic entries. They appear on the notebook's rule pages as if they were always there. Only a shinigami could confirm they're fake.
Also known as: 13-Day Rule, The Fake 13-Day Rule