My first NCIS fanfiction! I love the pairing of Tiva, and I've never had a good idea for them. But then this just popped into my head. A little bit of Tony's musings, and I had to throw in the Rules. Just had to.

**Note: Added Rule #40 in because I didn't beta-read this first.

Review and let me know how you like it!

Having been with NCIS for over ten years, Anthony "Tony" Dinozzo liked to think he had a pretty good read on the Rules. (At least, the ones that he knew of.) He didn't break them all that often (which saved him from brain damage more often than not).

Some of the Rules (always with a captial R, even when you think it) are absolute. Others can be bent (which he is prone to do at times). Very few can be broken short of life-threatening situations, and even then there's some issues regarding how well it'll blow over once the situation calms down.

Then he met Ziva David, became her partner, and learned just how hard it was to keep those Rules pristine and intact. (But then again, his ninja never made anything easy for him.)

Rule #1 (both of them) were no-brainers. (But "Never screw over your partner" was hard to do when pretty much everything he did was bound to screw her over sooner or later.)

Rule #2 kept him secure in his job. God forbid he ever forget his gloves at the scene. (But even if he did, she'd have a spare pair for him, just in case.)

Rule #3 ("Never be unreachable" his 5-out-of-5 ass. Gibbs dropped off the face of the planet like a mole gone to earth) was his ongoing torture. They didn't have to check and double-check every little thing about each other anymore (not since that undercover op with Jeanne and Ziva was all inappropriate-touching nosy ninja) but they can still be unreachable to each other. (Guarded hearts, stifled feelings...there are several ways that he remains unreachable. She just doesn't realize.)

Rule #4 kept him alive while undercover with Jeanne - nobody knew. Not even Gibbs. Not even his partner. (But God, how he'd wanted to tell her about it. She would've been his one other person - if he'd been allowed.)

Rule #5 got him into NCIS in the first place, spoken outside Human Resources by Gibbs that day he walked out of Baltimore PD. (It was also the words that he tried to convey to her when she talked about leaving.)

Rule #6 is one of the Rules that can be broken several times with good reason. They apologize for a lot (him, for Jeanne and Jenny and Michael; her, for Ari and Jenny and Michael) and mostly for things that were out of their control (her getting shipped home, him being reassigned Agent Afloat, the whole Somalia debacle) but most of all, they apologized for being themselves. (He's a deck of jokers, she's serious as a heart attack.)

Rule #7 had saved his ass more than once. (And hers too.) The only way to break this Rule was to stop lying (like he did to tell Jeanne) or to trip up in his words (which he did at times around her) when he wasn't paying attention. (But so far, he'd managed to keep his true feelings for her safely hidden behind specific lies designed to keep it secret.)

Rule #8 was thrown in his face every single day. With each new case, each new danger, every situation that they came across, Tony never took his partner for granted. (He learned that the hard way with Kate - one day there, the next gone.)

Rule #9 had become second nature long ago. (But when she pulled out that monster blade from her boot, damn if he didn't feel a little emasculated.)

Rule #10 was a big one. One of the Never-Breakers (break this Rule without a pressing need, and your ass is grass). He didn't get personally involved on many cases (except with Jeanne, and when Jenny was killed) but when he broke this Rule, he knew it was the only way. (If he hadn't, she would've never made it out of Somalia alive. Her father sure as hell wasn't going to rescue her, so that left him.)

Rule #11 sometimes gave him trouble. (Still does from time to time.) But he knew why it was in place, and why he had to follow it. (But leaving her in Tel Aviv without mending that bridge weighted heavy on his heart for months afterwards.)

Rule #12 was another Never-Breaker. History was rife with examples (Gibbs and Jenny, Abby and McGee, him and EJ) of why this particular Rule existed. (Though in all fairness, Abby and McGee really didn't bomb so much as...cool down to friendship.) So every time he was with a woman (which was few and far between these days - a side-effect of growing up) he had to focus and not imagine it was her (because not only would Gibbs kill him, but she would too.) or, God forbid, flash back to when they were undercover together. (That was just too much torture on the lonely nights he couldn't get to sleep.)

Rule #13 wasn't a Rule that affected him much in the day-to-day scheme of life. (Thank God - probably just a Gibbs-specific rule.) But lawyers were right up there with people that managed to intimidate him. (Along with his mother and her. Always her. Damn, sexual-fantasy Kate had been right.)

Rule #15 was a challenge some days. (Teamwork still came hard for his assassin at times.) But when they fell into their groove, nothing could stop them.

Rule #16 holds special meaning for him. Very rarely do they actually get to use it, but when they do, it's only when they're really, really pissed off. (So when Cobb sat in the Interrogation Room with that smug smile, knowing where she was, Tony felt it was an appropriate application.)

Rule #18 clashes with Rule #6, but doesn't cancel it out. (Apologizing doesn't technically mean you're forgiven.) Which is actually a good thing, considering all the crap that they do to get a case solved. (Like that bomb in the terrorists' warehouse.) They required a lot of asking for forgiveness.

Rule #22 is a staple among the MCR team. (They should include it in NCIS agent training at Fletzy, for real.) Gibbs had a mojo when he went in that room, and interrupting it always had dire consequences. (She had better luck than he did in that department; aside from Abby, she was undoubtedly the favorite.)

Rule #23 is the Never-Breaker of all Never-Breakers. It's like a code from God. (One he's followed faithfully from day one.) Thankfull he'd never encouraged the wrath of the Marine. (But if she ever started drinking coffee, he'd have to amend it to "...the Marine's or Ninja's coffee...")

Rule #27 was always tricky. (Other than the fact that she's a ninja with Jedi mind powers.) She doesn't like being followed. And it's damn impossible to follow her, seen or unseen. (But then again, he's gotten a lot better at following her either way.)

Rule #35 has gotten more than its fair share of use. (Problem is, when the watcher is his ninja partner, he sometimes forgets that she doesn't like to be watched.)

Rule #38 only happened to him once, after Gibbs came back, but it was a very rewarding experience. (Especially when she stuck by him like glue afterwards.) But honestly, he preferred being Senior Field Agent (that and he felt somewhat wrong ordering Gibbs around) and, truth be told, he thinks she preferred it too. (She told him that later, in a tone that said "Don't disagree with me.") Besides, he felt like he was missing his left arm if she wasn't his partner.

Rule #39 was one of the Rules that he'd questioned every day since she arrived at NCIS. (What were the odds that the control officer for the Mossad rogue who killed his former partner was the woman who would become his partner?)

Rule #40 is something he's learned to live with. (With the amount of pranks he's played on her over the years, she's always out to get him.)

Rule #44 was something ingrained in him (male protectiveness, he guessed) but raised a spot of contention with her. ("I am perfectly capable of defending myself, DiNozzo!" was her trademark retort.) But if children are involved, that's when she decides to obey the Rule. (Female protectiveness, he guessed.)

Rule #45 kept them all on their toes. (Nobody wanted Gibbs on their butts for a mess they made.) But he always tried to clean up the messes that made her sad. (Like the whole issue with Ray lying to her.) If it helped her smile, he'd go in armed with Brawny towels and a power washer.

Tony learned a lot from Gibbs. The Rules were the foundation of that learning process.

Then he met Ziva. And those foundations were shaken. (That, and the fact that he thought she was crazy sexy from the first moment he saw her.) Then they got close (closer than he'd ever been with any woman before or since) and they became friends.

Fifty Rules. They were absolute. (Just like Gibbs.) They were unshakeable. (Except when the need to break them outweight the consequences of breaking them.)

Then Rule #51 came into existance.

Rule #51 was his saving grace. (Always nice to know Gibbs is human, even if it's believed he's a fallen god.) It gives him a faint glimmer of hope (which has been remarkably persistant for the last seven years).

Because that's how he knows that someday, he'd have a chance with her.

Rule #12 be damned. He will have a chance with her.

But he's willing to wait for her. Always has, always will.