. Said tribe was planning to'sacrifice' it into a a small volcanic vent near by that had a portal to the plane of fire.
Said tribe had a high regard for elves, so the party's elven thief was trying to pretend to be a priest of Ra to convince them to give it to her and her 2 guards (most of the party were invisible, providing special effects). She makes a comment about Ra and the full moon in the evening sky, at which point my (invisible) character whispers in her ear 'Ra's a _sun_ god.' She starts to panic and shouts "Ra, Ra, Ra" and I (being a smartass) respond 'Shish boom bah' at which point we all collapsed laughing.
Hmm... I don't know about combat modifiers or the like, but a few things have been named that way. For example, a party a couple years ago owed several thousand gold to the head priest of the cleric's deity (they had convinced him to resurrect a party member on credit). After a couple sessions, they had accumulated a few hundred GP, and were debating whether to return to the city and make a partial payment, or to keep traveling and earn more money. Then one of the players piped up, "Let's just go see the goddamn pope and give him what we have so that the pope-o-meter goes down."
I never got them to stop calling the high priest "the pope," even in-character, and eventually gave up the fight. And to this day, any debt the party accrues is measured on the "pope-o-meter."
Similarly, "make a con check" has become the euphemism du jour for'self-enjoyment.' And after one particularly embarrassing (for me) session of dungeon-delving where I, as DM kept saying 'T-intersection' when I meant '4-way intersection, all descriptions of T-intersections have henceforth been met with a derisive chorus of "Big T or little t?"
And for almost a decade now, one on-again-off-again party of mine has insisted on describing their marches in Oregon Trail-style, e.g. "We set off at a strenuous pace, eating filling rations." They've done this ever since one of the party members got sick from drinking from a stream and an expedition had to be delayed, which inspired one player to shout, "So and so has dysentery! Lose 3 days!"
And there was one time when a party member (who was alone and probably only level 4 or so) encountered a pair of fire elementals.   After that, any time somebody found themselves up against a foe they couldn't beat, they'd declare, "Good think I'm not wearing any pants!" Yes, that's an instance of memetic mutation within a D&D party.
I could go on (and on...) but those are a few that stuck out to me.
In a similar vein, I was playing a game in which we met a corrupt mayor, who the DM had named "Fieten" (Pronounced "Fightin'"). I immediately asked if his last name was "Irish". For the rest of the game, he was referred to as "The Fightin' Irish", much to the DM's annoyance.
In a game my sister's running to get my family into D&D, she put in a NPC called Duven Stoll. My little brother and I immediately named him Doofenschmirtz.
In my case, a casual comment taken by the GM has had consequences on EVERY CHARACTER I'VE PLAYED SINCE!
It starts with my first Paladin. I had decided that an integral part of his paladin vows was that he would make a good effort to avoid any fight he came across by diplomacy or another nonviolent method - not that he didn't fight when he had to, and of the two melee characters in the party he was the one with the tower shield and the full plate and the improved toughness.
Anyway, the GM thought he was real clever by putting us into an arena where we were forced to fight to the death. He thought he was really supremely clever when he had my character chained and forced to fight a drider. That's when somebody made the off-hand comment that a Drider archer is at least 50% hawt.
Then I surprised the hell out of everyone by RPing my way out of the conflict - I didn't even need a nat 20 on my diplomacy check to make her an ally, I simply RPed my character's proposal: the trip would kiss, make the crowd go wild, and then they both could get out of the arena alive. It means I have to kill one less sentient, and if it doesn't work I figure I can take her (lol probably not as I was third level at the time).
Turns out Driders make clingy girlfriends (haha get it because they're SPIDERS I slay me), and long story short, my Paladin was in way over his head. The problem is that this one bit of RP has since come to color every single RP interaction I've had in that group - whether it's Yuan Ti or Blue Dragons, we've made more off-color jokes at my character's expense than I can think to list here.
I didn't sign up to be the comedy relief, it just sort of happened.
I joined a group of friends in an Exalted campaign once - we all live in different states, so we played via Skype. At some point I appropriated a magic hand-mirror from an enemy who had been using it as a communication device; some time later, I get a call on it while away from the rest of the party, and find myself (and my tagalong npc) talking to the game's biggest bad yet. She turns out to be a civilized kind of evil, so we exchange pleasantries and then come to the awkward moment where she asks for my name. As my mind blanks, the other players suggest ridiculous made-up names like Tedathy Nickthaniel or Big McLargehuge. At a pause in the proceedings, I say in a total deadpan the name of one of the other player characters.
That day I learned that one of the group's house rules is that anything that makes the DM laugh for more than 15 seconds is considered canon.
My teammate was less than pleased.
The campaign went on hiatus before we got to meet the lady in the mirror, but roleplaying my character's worrying and eventual in-game confession was unexpectedly entertaining.
while adventuring, there was a magic well that was throwing off all our rolls. i off-handedly mentioned that i needed to pee while absentmindedly rolling a d-20. i accidentally rolled a nat 20, and the DM decided that my strong dwarven piss deactivated the powers of the well, and i saved the party like that.
Well... just last week my D&D group got together for our usual routine: Spending the first hour and a half figuring out where everyone is. Literally, the only person who knows where any of our party members is at the start of the session is the player of the character themselves. Well, it just so happened our elven favored soul was "resting" in her favorite tree on her favorite branch. She kept talking about it for awhile, so (in a joking light-hearted, totally not serious way) I said that I break said branch out of the tree. The D.M. heard me.
Hell yeah I took the credits. Guy was sold and in a cage before he realized what just went down.
... my Paladin is now a eunuch.
Speaking of names, I had one character I ended up naming 'Tabeed'. This was because I was having trouble thinking up a name and jotted down the letters 'TBD' (To Be Decided), then tried pronouncing them.
I've also made Monk characters and named them 'Feng Shuey'.
My friends and I were playing a rather high level 3.5 game set in the Silver Marches in Faerun and we stumbled upon a 'troll city'. We crept up to the gates intending to make a sneak attack when one of the trolls noticed us and screamed. Our quick thinking Bard rolled high enough initiative and charmed the troll, convincing him we were here to repair the gate. Now whenever we sneak up on enemies we are repairing the gate.
Well, I have one time when I, as the GM, made a casual remark that had extraordinary consequences...
So I was running a Battlestar Galactica campaign with a rather large group of players. In which, the players in their ship come across a few civiilian ships, which I decided would be Zoo and Botany ships, off the cuff.
Somewhat brought up a complex, unrelated, rules issue, so whilst I looked it up to give the players something to do I made two of them play the roles of the captains of the civvie ships and negotiate with the players.
Minutes later the player performing as the Admiral had transported a bear over the players ship ( At the cost of two lightly gored marines). This bear was then put into a ball pit. In which the Admiral would frolick with the bear, in the ball pit, in his off hours.
I looked up at this point, groaned, but allowed it because I didn't think it would affect much and the player already seemed rather attached to the bear.
A certaon faction of the players was trying to raise a revolution in the ship against the Admiral. So they assainated the bear