Doctor Princess Twilight Sparkle's Notes On Pinkamena Diane Pie, henceforth "Pinkie" or "Pinkie Pie".
Initial thoughts:Chaos Magic infused? Not unless the Sonic Rainboom has Chaos Magic properties. Does it? No. Maybe we should look into- The ramifications of that being true are too widespread and horrifying to consider. Even for science.
Results of extended monitoring, trial and error, some well-placed hot-sauce, a particularly talkative canary, idle musings and Pinkie's own testimony.
Rule #1: Rule of Funny
This should be self-explanatory. As long as the action Pinkie Pie takes would result in de-facto humour, typically vaudeville in nature, it becomes possible, no matter how unlikely.
Rule #2: Rule of Cool
A subset of Rule of Funny, but wholly distinct from it. If Pinkie Pie truly believes the action taken would be more convenient for her - or that alternative actions would inconvenience her - Pinkie will be able to take a seemingly unlikely path of least resistance. This is because, as Pinkie herself puts it, it's not funny if she loses her cool. Rule of Cool is thus separate because they're actions to retain inherent comedic presence, but are not inherently funny. Rules one and two may have overlaps, like disappearing in a 'poof' of smoke at unreasonable velocity or bouncing up a forty-five degree mountainside.
Limits to Rules 1 and 2 to be tested in a sterile and controlled environment when researcher isn't wholly disconcerted by Pinkie Pie's insistence that, quote, "That'll be really fun to mess with, won't it?"
Rule #3: Rule of Win
Everything turns out well for Pinkie Pie in the end, no matter what. This has also been known to have drastic effects on causality. The experiments proposed by Schrödinger, for instance, would always result in Pinkie being alive. Not alive and dead. Just alive.
We have reason to believe this is because we live in a universe within the multiverse where Pinkie Pie cannot fail. A one-in-a-million chance will merely result in 999,999 parallel universes in which she does fail, and we will always occupy the millionth. Use of Pinkie Pie as a method to send simple binary messages to parallel universes through use of a coin-toss/guillotine setup pending.
Rule #4: Rule of Inverse Importance
The odds of Pinkie Pie knowing an unresearched fact is inversely proportional to how trivial that fact is.
Pinkie Pie knowing your birthday is 1:1. Pinkie Pie remembering her own birthday is significantly less.
Pinkie Pie knowing the millionth digit of pi is 1:1. Pinkie knowing the final digit to pi, or if there is a final digit of pi, is zero.
Proposal to graph this rule as a quadratic function has so far been unsuccessful, due to the inconsistent nature of the subject, and the difficulty to measure the value of 'importance'.
Rule #5: Rule of Musical Numbers
Anything that happens in a musical number, outside of the 1812 Overture, is non-canon unless otherwise explicitly stated or inferred outside of the musical number.
Don't ask me what that means. I'm trying very hard not to think about it.
Rule #6: Rule of Forgiveness
It is impossible to stay mad at Pinkie Pie. Many have tried. None have succeeded. Whether this is supernatural in nature or merely just her immutable personality is unknown.
Rule #7: Rule of Slapstick
Previously thought to be an extension of Rule of Funny, but I cannot believe that anypony could witness the horrific bodily trauma Pinkie Pie bounces back from - literally bounces back from - and find it amusing. Gorge rises in my gullet as I remember several severely horrific incidents being inflicted upon her surprisingly malleable form with little to no ill effect. I suppose this also explains how she withstands the G-Forces of her near-instant acceleration to what must be near-Mach-speeds from standing.
Rule #8: Rule of Three
Everything of minor but notable significance that occur in Pinkie's vicinity, i.e. researcher being slammed flat by a door, will occur in a set of three, with the most emphatic occurrence happening on the third.
When questioned on why this might be, Pinkie insisted "Because it's funniest that way!"
Rule #9: Rule of Hammerspace
Following similar rules as previously discovered Rule 4, Pinkie Pie can pull objects from what she refers to as 'hammerspace', so long as they serve no vital or significant purpose. If such an item appears to have some use to a 'plot-significant' situation, it will most often fail spectacularly.
'Plot-significant' is the phrase Pinkie insists upon using. I have decided to humour her. She also tells me that the hammers in hammerspace tend to be unwieldy and impractical, which makes them lots of fun at carnival games. Once more I am forced to take her word on this.
Rule #10: Rule of 'Meta'
This one's odd. This exists purely because of Pinkie's insistence, and unwillingness to back down on the matter, so I'm inclined to leave it in for posterity:
"Meta-humour just isn't funny anymore, guys and gals. Breaking the fourth wall might have been funny once but everypony knows it just isn't anymore. It's just bad. On that note, MrNumbers probably crossed the line just by writing this, but it's just for a teensy-weensy comment and not for a story or anything -- maaaybe a blogpost at worst -- so he's probably going to get away with it."
My apologies to Mr. Numbers on the committee approving this for publication: She also insisted on not using the period in your title. I know, Abacus, but when I asked her why, she got really weird, even by Pinkie's standards.
Rule #11: Pinkie Pie Will Defy Expectations
Even these rules are not as concrete as they otherwise seem. Pinkie says that, now that they've been observed, they might not work sometimes because comedy is all about subverting the expected.
The possibility of Pinkie Pie's effects being of a quantum nature, changing under observation, is not lost on me. Further study is needed.