What Are Gibbs' Top 10 Rules On NCIS?

NCIS is a show that thrives because of its strong characters. While supporting players like Abby Sciuto (Pauley Perrette) and Tim McGee (Sean Murray) sometimes grab the spotlight, the series' protagonist, Leroy Jethro Gibbs (Mark Harmon), is its rock. Gibbs is a former marine sniper, a bit of a tough nut to crack, but loyal and unafraid to let his squad mates poke a little fun at him. 

One of NCIS' longest-running bits and a frequent source of character humor is Gibbs' ever-growing list of rules to live by. First introduced on the pilot episode of the series, Gibbs' lessons were, according to the man himself, passed down to him during his marine training. Over the years, though, his colleagues have begun to suspect they're actually his own homespun wisdom. Either way, throughout the show's nearly two decades, they've been a constant fixture.

Since Gibbs has a classic Type-A personality, his rules are organized on a numbered list that he seemingly has memorized to the letter and keeps stored in his mind. However, they're dispensed only as needed, so it's taken fans years to document them, with individual entries often left blank for many seasons. As of season 17, just under 50 of Gibbs' rules have been dispensed, but we'll take a look at the top 10 to get a sense of what kind of wisdom he has to offer.

Gibbs' first three rules are introduced on the first-ever episode of NCIS, "Yankee White," in the midst of an investigation into the death of a Navy commander. All three of these rules pertain to police work, and are dolled out to Secret Service Agent Caitlin Todd (Sasha Alexander), who's assisting the NCIS team with the investigation.

The first, "Never let suspects stay together," is a pretty good tip for someone unfamiliar with police work; the second, "Always wear gloves at a crime scene," feels more like something anyone who has watched Law & Order would know. The third rule has a practical application even outside of the world of crime investigation: "Don't believe what you're told. Double check."

The rest of Gibbs' first five rules are listed on later episodes of the series. Rule number four, dished out on the season 4 episode "Blowback," is another solid piece of life advice. After revealing that she's been keeping something from him, NCIS Director Jenny Shephard (Lauren Holly) cites Gibbs' own fourth rule: "Best way to keep a secret: keep it to yourself. Second best way: tell one other person if you must. There is no third best."

We learn rule five at the end of the season 8 episode "Baltimore," when a discouraged cop confides in Gibbs that he doesn't want to be on the force anymore. Gibbs responds with his fifth rule, "You don't waste good," to encourage him to not quit.

The next five rules are a mixed bag of great life advice and questionable credos that not even Gibbs himself lives by. Rule six is prosperous — "Never say you're sorry. It's a sign of weakness." — but Gibbs himself has apologized to multiple people during his time working with the Naval Criminal Investigative Service. "Always be specific when you lie," rule seven, may be a bit morally ambiguous, but if you are going to lie, it's good advice.

Rules eight and nine are wildly different in tone and usefulness. "Never take anything for granted" sounds like Gibbs stole the sentiment from an inspirational coffee mug. "Never go anywhere without a knife" is certainly a lot more specific. In the context of police work, it sounds quite sinister, but for those of us who might need to cut an errant string or do some quick whittling, it's just good practical advice.

The last rule in Gibbs' top 10 is another one he doesn't always live by. At the end of the season 7 episode "Obsession," a team member reveals that he broke the rule, "Never get personally involved in a case." Gibbs reassures him by admitting, "That's the rule I've always had the most trouble with."

Although he pioneered the practice, Gibbs isn't the only NCIS team member with rules. Throughout the show's run, several of the characters have adopted their own personal guidelines. Fan-favorite character Abby Sciuto, the goofy yin to Gibbs' serious yang, has several of her own. Number one is very straightforward: "Do not lie to Abby." The only other rule of Abby's that we've been privy to, "Always keep a spare," is a reference to her addiction to a fictional caffeinated soft drink called Caf-Pow.

Other team members have rules inspired by their own particular life circumstances and areas of expertise. Medical Examiner Jimmy Palmer (Brian Dietzen) lives by the law of "Pipettes can never be too clean," while retired Mossad agent Ziva David (Cote de Pablo) borrowed her former employer's saying that "knives don't run out of bullets."

While we're still waiting to find out all of Gibbs' rules (17, 19, and 24 through 26 are still a mystery, among others), given the NCIS' staying power, there's a good chance we'll have a completed list of insights to live by when the show finally wraps up.