‘NCIS’: How Mark Harmon’s ‘Gibbs’ Rules’ Came to Be and the Ones That We All Should Live By

by Suzanne Halliburton

Leroy Jethro Gibbs, the NCIS special agent in charge, lives by a creed, his own set of special life rules. Maybe he makes them up on the spot. Perhaps he borrowed several of them.

But NCIS fans know this: Gibbs, portrayed by Mark Harmon, likes to teach his agents and friends about the Gibbs rules.

We learned another one in the season 18 finale. That would be rule No. 91. Yes, there are lots of Gibbs rules. But he named his boat Rule No. 91. Ellie Bishop, a fellow NCIS agent, asked Gibbs about rule 91.

He told her: “You’re living it. When you decide to walk away, don’t look back.” Moments later, Gibbs’ boat blew up, but we see that he survived the blast and is swimming away. Is he following the rule of walking away and not looking back? We know that Bishop is in the process of fulfilling rule 91. The character is taking on a covert assignment.

NCIS Fans Maintain Database with Gibbs Rules.

Throughout the NCIS series run, Gibbs has mentioned his rules. Fans even track them as writers toss out gems for Harmon to say as he plays Gibbs. The initial best guess was that Gibbs adopted them from his background in the Marines. H

However, a fan site devoted to all things NCIS documented this factoid. In season six, Gibbs confessed he got the rules from his wife, Shannon. She told him when they first met: “Everyone needs a code they can live by.” That sounds like a very livable rule.

But the only rule of Shannon’s that Gibbs ever quoted during an NCIS episode was “never date a lumberjack.” Through the first three seasons, Gibbs told agent Ziva David that there would be 50 rules he needed to teach her.

CBS, which broadcasts NCIS, even keeps track of some of the Gibbs rules in a photo gallery. You can check the rules here. Or, do a simple search on Amazon and buy a mouse pad or tin sign adorned with Gibbs words to live by.

Some Episodes Named for Gibbs Mottos

Some of the NCIS episodes are named in honor of Gibbs’ rules. That was the case in the finale of season seven. It was called Rule 51. That’s when fans learned that Gibbs writes rules down as they come to him. He keeps the pages in a tin somewhere in his home. So what was rule 51?

“Sometimes you’re wrong.”

Again, what a perfect rule to live by.

There are some real Gibbs’ pearls. Like this one: “If you feel like you are being played, you probably are.” That’s rule 36. How about “When you need help, ask.” Or “Always watch the watchers.”

Gibbs freely admits that some of his NCIS past is shady. Maybe that’s where he created some of his rules. Rule No. 7 is “Always be specific when you lie.” Or, “if someone thinks they have the upper hand, break it.”

Some, he borrowed from other characters. Like “never say you’re sorry, it’s a sign of weakness.” He reworked that line from a John Wayne movie. That brings up another Gibbs rule: “Never meet your heroes.” That’s rule No. 73.

And finally, there’s another good NCIS rule via Gibbs to live by: “Clean up the mess that you make.” That’s No. 45. Perfect time to start cleaning.