Rule #1: Never let suspects stay together. (Franks) 1x01 'Yankee White'

Rule #1: Never screw over your partner. 4x14 'Blowback' 

Rule #2: Always wear gloves at a crime scene.
(Franks) 1x01 'Yankee White'

Rule #3: Don't believe what you're told. Double check.
(Franks) 1x01 'Yankee White'

Rule #3: Never be unreachable. 3x13 'Deception'

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. 4x11 'Blowback'

Rule #6: Never apologize — Its a sign of weakness. A rule used more often than the others, but finally given a number in 7x12 'Flesh and Blood' during a great Gibbs/DiNozzo moment. The first person to use that phrase was John Wayne in, "She Wore a Yellow Ribbon." "Never apologize, mister, it. It's a sign of weakness." — In the episode 3x23 'Hiatus Part-1' DiNozzo explains to NCIS Director, Jenny Shepard, that Gibbs took this one from "The Duke himself."

Rule #7: Always be specific when you lie.
1x23 'Reveille'

Rule #8: Never take anything for granted.
3x10 'Probie'

Rule #9: Never go anywhere without a knife.
1x13 'One Shot, One Kill' & 1x20 'Missing'

Rule #10: Never get personally involved on a case. (Said by Tony, agreed on by Gibbs)
7x21 'Obsession'

Rule #11: When the job is done, walk away.
6x24 'Semper Fidelis'

Rule #12: Never date a coworker. 1x15 'Enigma'

Rule #13: Never, ever involve a lawyer. 6x07 'Collateral Damage' & 7x24 'Rule Fifty-One'

Rule #15: Always work as a team. 5x05 'Leap of Faith'

Rule #18: It's better to seek forgiveness than ask permission. 3x04 'Silver War'

Rule #22: Never, ever bother Gibbs in interrogation.
4x10 'Smoked'

Rule #23: Never mess with a Marine's coffee if you want to live.
2x09 'Forced Entry'

Rule #27: Two ways to follow: — First way they never notice you, — second way they only notice you. 7x15 'Jack Knife' &
7x24 'Rule Fifty-One'

Rule #38: Your case, your lead. 6x16 'Bounce'

Rule #39: There is no such thing as coincidence.
7x21 'Obsession'

"The 40's are for Emergency Use Only!"
7x24 'Rule Fifty-One' (Mentioned by Abby)

Rule #40: If it seems someone is out to get you, they are.
(Said by Abby, agreed on by Gibbs) 7x22 'Borderland'
& 7x24 'Rule Fifty-One'

Rule #44: First things first. Hide the women and children. 7x23 'Patriot Down'

Rule #45: *PENDING* Gibbs Said, "Left a mess I've got to clean up." 7x24 'Rule Fifty-One' (See Below)

Rule #51: Sometimes — You're Wrong! 7x24 'Rule Fifty-One'

 

 

 

   

And remember. . .

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

---

NOTES:

In 3x05 'Switch' we learn there are actually about 50 Rules. In 3x15 'Deception' the writers seem to have forgotten that they already used Rule #3. A new Rule #1 is given in episode 4x11 'Blowback' creating another duplicate. Some have speculated that the original Rules #1 and #3 are actually 'Crime Scene Rules' and not Gibbs' Rules. There are also theories that because the rules are not written down, the numbers may be fluid. Regardless, we now have two versions of Rule #1 and Rule #3. However, with the Season 7 Finale 3x15 'Deception', we have some clarification that Gibbs' Rule #3 is actually "Never be unreachable." At the end of the episode, Rule #3 is visible on a scrap of paper inside the box. That makes sense since the Gibbs' Rule #3 wasn't mentioned until season 3 when the writers had put at least a little thought into Gibbs having a set of rules. Using that theory, it also makes sense that Gibbs Rule #1 is "Never screw over your partner," mentioned the first time in season 4.

Here is NCIS Executive Producer Shane Brennan’s long-awaited and surprising explanation:

“Gibbs lives his life by a set of rules that took root from the first day he met Shannon. Over time, Gibbs added to the rules. When he joined NIS, Mike Franks told him he didn't need dozens of different rules to be an agent... just three 'golden rules.' And this is why we have double ups on rules #1 and #3. Three of them are Gibbs' rules; three of them are Mike Franks’ rules. We are still to reveal the double-up on rule #2. And it's up to the fans to guess which of the rules were Mike Franks’ three golden rules and which were Gibbs'.”

One of Gibbs' Rules that has not been strictly followed is Rule #6, "Never apologize. It's a sign of weakness." Another is Rule #3, "Never be unreachable." Gobbs often leaves his cell phone behind when he does not want to be reached. Recently we learned that Gibbs' Rule #6 is "Never apologize — It's a sign of weakness." Gibbs has made at least six exceptions to Rule #6:

    1. His apology to Kate for being late to her funeral.
    2. His apology to McGee for not backing him up when he was interrogated.
        (and arrested) by the DC Metro Police.
    3. His apology to Franks because of his amnesia.
    4. His apology to Ducky following his return from Mexico.
    5. His apology to Joann for not being able to protect Shannon and Kelly.
    6. His apology to Abby in the Season 7 Finale, Rule Fifty-One.