Rule #1: Never screw over your partner.
Rule #2: Always wear gloves at a crime scene.
Rule #3: Never 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 #5: You don't waste good. (…"You're Good" Gibbs says to DiNozzo) '

Rule #6: Never apologize  Its a sign of weakness.

Rule #7: Always be specific when you lie.

Rule #8: Never take anything for granted.

Rule #9: Never go anywhere without a knife.

Rule #10: Never get personally involved on a case. (Said by Tony, agreed on by Gibbs)

Rule #11: When the job is done, walk away.

Rule #12: Never date a coworker.

Rule #13: Never, ever involve a lawyer.

Rule #15: Always work as a team.

Rule #16: If someone thinks they have the upper-hand,
…break it! (DiNozzo)

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: Two ways to follow: First way, they never notice you,  second way, they only notice you.

Rule #35: Always watch the watchers.

Rule #38: Your case, your lead.

Rule #39: There is no such thing as coincidence.

"The 40's are for Emergency Use Only!"
(Mentioned by Abby)

Rule #40: If it seems someone is out to get you, they are. (Said by Abby, agreed on by Gibbs)

Rule #44: First things first. Hide the women and children.

Rule #45: Clean up your own mess. (Gibbs Said, "Left a mess I've got to clean up."  DiNozzo commented that's basically Rule #45)

Rule #51: Sometimes  You're Wrong!

And remember…

"A slap to the face
is an insult  to the
back of the head
is a wake-up call."