NCIS is made up of an interesting cast of characters. Fans will agree the most interesting in the bunch is Agent Leroy Jethro Gibbs (Mark Harmon). One thing that makes him stand out from the rest is the fact that he has a set of rules he expects everyone on the team to follow. There are 69 rules, but not all of them have been revealed. Here’s a rundown of Gibbs’ rules.

Mark Harmon and Sean Murray | Bill Inoshita/CBS via Getty Images

Rule 1: Never let suspects sit together. This rule was first mentioned in an episode titled “Yankee White,” which aired during NCIS’ very first episode in Season 1.

Other Rule 1: Never screw over your partner. Gibbs has two No. 1 rules. This one involves having your partner’s back. Gibbs first mentioned this rule during an episode titled “Blowback” (Episode 14, Season 4).

Rule 2: Always wear gloves at a crime scene. Gibbs is very strict about making sure his team members stay safe when investigating a crime scene. That’s why he requires everyone to wear gloves. Rule 2 was mentioned during “Yankee White” (Episode 1, Season 1).

Rule 3: Never believe what you are told. Double check. This is a good rule for work and life in general. Gibbs was on to something here. He first mentioned this rule during “Yankee White” (Episode 1, Season 1).

Mark Harmon and Pauley Perrette | Sonja Flemming/CBS via Getty Images

Other Rule 3: Never be unreachable. Gibbs wants to make sure team members are always able to contact each other. That’s why he insists that no one is unreachable. This rule is first mentioned in “Deception” (Episode 13, Season 3).

Rule 4: Best way to keep a secret. Keep it to yourself. Second-best, tell one other person—if you must. There is no third best. Gibbs and secrets go hand in hand (until recently, that is). He believes the best way to keep a secret is to only tell a select group of people. This rule is first mentioned during “Blowback” (Episode 14, Season 4).

Rule 5: You don’t waste good. Whatever it is, if something is good, don’t waste it. This rule is first mentioned in “Baltimore” (Episode 22, Season 8).

Mark Harmon and Maria Bello | Bill Inoshita/CBS via Getty Images

Rule 6: Never say you’re sorry. It might sound rude, but Gibbs strongly believes in keeping the word “sorry” out of your vocabulary. This rule is first mentioned in “Flesh and Bone” (Episode 12, Season 7).

Rule 7: Always be specific when you lie. If you’re going to lie, be specific. This rule is first mentioned in “Reveille” (Episode 23, Season 1).

Rule 8: Never take anything for granted. No one knows better than Gibbs that you never know how long you’re going to have someone or something. This rule is first mentioned in “Probie” (Episode 10, Season 3).

Rule 9: Never go anywhere without a knife. Gibbs always makes sure he has a weapon. This rule is first mentioned in “One Shot, One Kill” (Episode 13, Season 1).

Mark Harmon | Monty Brinton/CBS via Getty Images

Rule 10: Never get involved personally on a case. Gibbs recommends separating yourself from a case, so you can remain objective. This rule is first mentioned in “Obsession” (Episode 21, Season 7).

Rule 11: When the job is done, walk away. Gibbs doesn’t recommend dwelling on a closed case. This rule is first mentioned in “Semper Fidelis” (Episode 24, Season 6).

Rule 12: Never date a co-worker.Gibbs isn’t fond of the office romance. This rule is first mentioned in “Enigma” (Episode 15, Season 1).



Wilmer Valderrama as NCIS Special Agent Nicholas “Nick” Torres and Emily Wickersham as NCIS Special Agent Eleanor “Ellie” Bishop | Michael Yarish/CBS via Getty Images | Michael Yarish/CBS via Getty Images

Rule 13: Never involve lawyers. Gibbs also isn’t fond of lawyers. This rule is first mentioned in “Collateral Damage” (Episode 7, Season 6).

Rule 14: Bend the line, don’t break it. Agent Gibbs is all for his team members bending the line a bit, but he doesn’t want them to go too far. This rule is first mentioned in “Anonymous Was A Woman” (Episode 4, Season 11).

Rule 15: Always work as a team. For Gibbs, teamwork makes the dream work. This rule is first mentioned in “Leap of Faith” (Episode 5, Season 5).

Rule 16: If someone thinks he has the upper hand, break it. As you can see, Gibbs isn’t afraid of a little confrontation. This rule is first mentioned in “Pyramid” (Episode 24, Season 8).

Mark Harmon | Sonja Flemming/CBS via Getty Images

Rule 18: It’s better to seek forgiveness than ask permission. So far, rule 17 hasn’t been revealed. Rule 18 is first mentioned in “Silver War” (Episode 4, Season 3).

Rule 20: Always look under. You never know what (or who) might be hiding underneath something. This rule is first mentioned in “The Artful Dodger” (Episode 17, Season 12).

Rule 22: Never, ever bother Gibbs in interrogation. The man doesn’t like to be bothered when he’s interrogating suspects. This rule is first mentioned in “Smoked” (Episode 10, Season 4).

Rule 23: Never mess with a Marine’s coffee if you want to live. Gibbs is quite serious about his morning cup of coffee. This rule is first mentioned in “Forced Entry” (Episode 9, Season 2).

It looks like someone tried to mess with Gibbs’ coffee | Richard Foreman/CBS (Photo by CBS via Getty Images

Rule 27: Two ways to follow someone. First way, they never notice you. Second way, they only notice you. If you’re going to follow someone, don’t be obvious–or be very obvious. This rule was first mentioned in “Jack-Knife” (Episode 15, Season 7).

Rule 28: When you need help, ask.This advice could save you at work. Gibbs rule 28 was first mentioned in “Blood Brothers” (Episode 10, Season 13).

Rule 35: Always watch the watchers.Is Gibbs paranoid? We don’t know, but this rule seems to work for him. Rule 35 was first mentioned in “Baltimore” (Episode 22, Season 8).

Rule 36: If it feels like you’re being played, you probably are. This rule can be followed in love and life. Rule 36 was first mentioned in “Nature of the Beast” (Episode 1, Season 9).

Mark Harmon and Pauley Perrette | Cliff Lipson/CBS via Getty Images

Rule 38: Your case, you’re lead. Gibbs is all about taking ownership of your work. Rule 38 is first mentioned in “Bounce” (Episode 16, Season 6).

Rule 39: There is no such thing as a coincidence. Gibbs doesn’t believe in coincidence. Rule 39 was first mentioned in “Obsession” (Episode 21, Season 7).

Rule 40: If it seems like someone’s out to get you, they are.Don’t ignore your instincts. Rule 40 was first introduced in “Rule Fifty-One” (Episode 24, Season 7).

Rule 42: Never accept an apology from somebody who just sucker-punched you. This one makes sense. Why would you trust someone who tried to hurt you? Rule 42 was introduced in “Psych Out” (Episode 16, Season 9).

Abby, Gibbs, and NCIS team| Sonja Flemming/CBS via Getty Images

Rule 44: First things first, hide the women and children. Gibbs is all about protecting women and children. Rule 44 was introduced in “Patriot Down” (Episode 23, Season 7).

Rule 45: Left a mess I gotta clean up. Gibbs doesn’t like a mess. Rule 45 was introduced in “Rule Fifty-One” (Episode 24, Season 7).

Rule 51: Sometimes you’re wrong. Gibbs doesn’t apologize, but he does acknowledge when he’s wrong. Rule 51 was introduced in “Rule Fifty-One” (Episode 24, Season 7).

Rule 62: Always give people space when they get off an elevator. We wish more people would follow this rule. Rule 62 was introduced in “Double Back” (Episode 13, Season 11).

The NCIS team in the elevator. | Ali Goldstein/CBS via Getty Images

Rule 69: Never trust a woman who doesn’t trust her man. We bet Gibbs is speaking from experience. Rule 69 was introduced in “Devil’s Triangle” (Episode 7, Season 9).

Read more: ‘NCIS’: How Mark Harmon Really Feels About Agent Gibbs

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