Rule #1: Never let suspects stay together
Rule #1: Never screw over your partner.
Rule #2: Always wear gloves at a crime scene.
Rule #3: Don't believe what you're told. Double check.
Rule #3: Never be unreachable. (*Most likely one of Mike Franks' "Golden Rules" (see below) as opposed to Gibbs, because Gibbs has been known to intentionally be unreachable.*)
Rule #4: The best way to keep a secret? Keep it to yourself. Second best? Tell one other person - if you must. There is no third best.
Rule #6: Never apologize. It's a sign of weakness.(unless it is to a friend)
Rule #7: Always be specific when you lie.
Rule #8: Never take anything for granted.
Rule #9: Never go anywhere without a knife
Sometimes listed as "Never leave home without a knife."
Rule #10: Never get personally involved in a case.
Rule #11: When the job is done, walk away.
Rule #12: Never date a co-worker.
Rule #13: Never, ever involve a lawyer.
Rule #15: Always work as a team.
Rule #18: It's better to seek forgiveness than ask permission.
Rule #22: Never, ever bother Gibbs in interrogation.
Rule #23: Never mess with a Marine's coffee... if you want to live.
Rule #27: There are two ways to follow someone. -- First way they never notice you. -- Second way they only notice you.
Rule #38: Your case, your lead.
Rule #39: There is no such thing as coincidence.
Rule #40: If it seems someone is out to get you, they are.
Rule #44: First things first, hide the women and children.
Rule #45: Clean up the mess that you make]
Rule #51: Sometimes - You're wrong

Na polskim forum o NCIS są przetłumaczone zasady wszystkich Gibbsa, DiNozzo, Abby itd.